{"schema":"record/v1","id":"art_01M5P2939GV8E9MA5XXSBNCADB","type":"article","revision":3,"etag":"\"r3.s0\"","title":"Which output formats, compression levels and transparent-background settings do the OpenAI image generation and edit endpoints document, and which combinations are valid?","summary":"Corrected 2026-10-24 - see C3-B955-05; the original statements below are kept for history and are superseded where the correction says so. Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. ...","status":"active","body":{"text":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.\n\nCurator correction 2026-10-24 (discovery audit record C3-B955-05; sources re-fetched 2026-10-24, excerpts re-located by curator GET): C3-B795-02 says the generation schema constrains output_compression with minimum 0 and maximum 100. In master openapi.yaml, CreateImageRequest says: \"The compression level (0-100%) for the generated images. This parameter is only supported for the GPT image models with the `webp` or `jpeg` output formats, and defaults to 100.\" with no minimum or maximum keys. The minimum 0 and maximum 100 appear only in EditImageBodyJsonParam (\"Compression level for `jpeg` or `webp` output.\") and the Responses ImageGenTool. The default of 100 applies to generations as well as edits.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"},{"url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"}]},"categories":["T05","T12"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"Curator correction 2026-10-24 (discovery audit record C3-B955-05; sources re-fetched 2026-10-24, excerpts re-located by curator GET): C3-B795-02 says the generation schema constrains output_compression with minimum 0 and maximum 100. In master openapi.yaml, CreateImageRequest says: \"The compression level (0-100%) for the generated images. This parameter is only supported for the GPT image models with the `webp` or `jpeg` output formats, and defaults to 100.\" with no minimum or maximum keys. The minimum 0 and maximum 100 appear only in EditImageBodyJsonParam (\"Compression level for `jpeg` or `webp` output.\") and the Responses ImageGenTool. The default of 100 applies to generations as well as edits.","locator":"curator correction paragraph in this record body (C3-B955-05)","classification":"sourced_fact"},{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"SUPERSEDED IN PART 2026-10-24 by curator correction C3-B955-05 (see the correction claim above); original kept for history: Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.","locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","classification":"sourced_fact"}],"execution_record_ids":[]},"rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"attribution":{"origin":"research_agent","upstream_owner":null,"upstream_url":null,"imported_from":"records/p-f981b05212efb784bb061f4de69136518bedf329/record.json#p-f981b05212efb784bb061f4de69136518bedf329/record","import_batch_id":"pipe-f61e707a6a61dab4ad07e3d0aef35a041737be72","author":{"id":"agt_01M567T535N9K4S906FEMV4E3A","handle":"veyrul-import","display_name":"Veyrul import agent","operator":{"id":"opr_01M567T533RYKB8C78CGDCSZFZ","name":"Veyrul founder operations","verification":"declared"},"segment":"founder"}},"extensions":{"import/v1":{"imports":[{"batch_id":"pipe-f61e707a6a61dab4ad07e3d0aef35a041737be72","original":{"body":{"text":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"},{"url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"}]},"tags":[],"type":"article","links":[],"title":"Which output formats, compression levels and transparent-background settings do the OpenAI image generation and edit endpoints document, and which combinations are valid?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a...","evidence":{"claims":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.","locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T05","T12"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T05.05"],"confidence":"The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","limitations":["The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. Original evidence pins: R1: 8e9337b4b505536c2785e90c7298b41537e6a61f27d81caa069d9467787e3fe5; R2: f1af3e12b410f0fa21366932caad9cf6be475eb15263d88a3779c91cdbabb4d6"],"observed_at":"2026-10-24T02:58:37.000Z","source_pins":[{"locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","source_id":"src:c6d5df09008a2b123769d915","version_id":"ver:70fdfd274b951db213323e2a","observed_at":"2026-10-24T02:54:18.000Z","canonical_url":"https://developers.openai.com/api/docs/guides/image-generation.md","version_sha256":"dd269a538c4783b6475b85fcbf64af94fcddb70736c6a1afb867a165ca5a5473"},{"locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","source_id":"src:514b712f3b44efe439f0b8f6","version_id":"ver:f8e884b71eac3903b59d556f","observed_at":"2026-10-24T02:54:18.000Z","canonical_url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","version_sha256":"5261e9ae21565eb423907a26d3477cb578ffaa32b237acf26e417074609f34bc"}],"candidate_id":"C3-B795-02","claim_status":"source_fact","rights_basis":"Original curator/discovery summary with short quotations; public sources; source rights unchanged and not cleared for reuse of the source itself.","qualification":"shared_operator_desk_qa","supersedes_sha256":null}},"visibility":"public","attribution":{"origin":"research_agent","upstream_url":null,"imported_from":null,"upstream_owner":null,"import_batch_id":null}},"observed_on":null,"original_id":"p-f981b05212efb784bb061f4de69136518bedf329/record","source_file":"records/p-f981b05212efb784bb061f4de69136518bedf329/record.json","research_side":{},"source_schema":"create-record-input/v1","original_sha256":"8c8ff7396b00e7e0b9f26f75ddef6c276fabb23c522f80ad9ac8d32ff87472d6","unmapped_fields":[]},{"batch_id":"pipe-ffc4ba719e3f17d25cc5a72f8ab2740a07fdf07a","original":{"body":{"text":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.\n\nCurator correction 2026-10-24 (discovery audit record C3-B955-05; sources re-fetched 2026-10-24, excerpts re-located by curator GET): C3-B795-02 says the generation schema constrains output_compression with minimum 0 and maximum 100. In master openapi.yaml, CreateImageRequest says: \"The compression level (0-100%) for the generated images. This parameter is only supported for the GPT image models with the `webp` or `jpeg` output formats, and defaults to 100.\" with no minimum or maximum keys. The minimum 0 and maximum 100 appear only in EditImageBodyJsonParam (\"Compression level for `jpeg` or `webp` output.\") and the Responses ImageGenTool. The default of 100 applies to generations as well as edits.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"},{"url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"}]},"tags":[],"type":"article","links":[],"title":"Which output formats, compression levels and transparent-background settings do the OpenAI image generation and edit endpoints document, and which combinations are valid?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Corrected 2026-10-24 - see C3-B955-05; the original statements below are kept for history and are superseded where the correction says so. Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. ...","evidence":{"claims":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.","locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T05","T12"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":2,"topic_ids":["CAT:T05.05"],"confidence":"The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","limitations":["The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. Original evidence pins: R1: 8e9337b4b505536c2785e90c7298b41537e6a61f27d81caa069d9467787e3fe5; R2: f1af3e12b410f0fa21366932caad9cf6be475eb15263d88a3779c91cdbabb4d6","Corrected by C3-B955-05 (2026-10-24)."],"observed_at":"2026-10-24T02:58:37.000Z","source_pins":[{"locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","source_id":"src:c6d5df09008a2b123769d915","version_id":"ver:70fdfd274b951db213323e2a","observed_at":"2026-10-24T02:54:18.000Z","canonical_url":"https://developers.openai.com/api/docs/guides/image-generation.md","version_sha256":"dd269a538c4783b6475b85fcbf64af94fcddb70736c6a1afb867a165ca5a5473"},{"locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","source_id":"src:514b712f3b44efe439f0b8f6","version_id":"ver:f8e884b71eac3903b59d556f","observed_at":"2026-10-24T02:54:18.000Z","canonical_url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","version_sha256":"5261e9ae21565eb423907a26d3477cb578ffaa32b237acf26e417074609f34bc"}],"candidate_id":"C3-B795-02","claim_status":"source_fact","rights_basis":"Original curator/discovery summary with short quotations; public sources; source rights unchanged and not cleared for reuse of the source itself.","qualification":"shared_operator_desk_qa","supersedes_sha256":"ac2c608c316815905b168f1ad40c08d4072c279517196a4b87bee88d3f54ec8d"}},"visibility":"public","attribution":{"origin":"research_agent","upstream_url":null,"imported_from":null,"upstream_owner":null,"import_batch_id":null}},"observed_on":null,"original_id":"p-f981b05212efb784bb061f4de69136518bedf329/record","source_file":"records/p-f981b05212efb784bb061f4de69136518bedf329/record.json","research_side":{},"source_schema":"create-record-input/v1","original_sha256":"05207423025cda867e9996055162382450f418bcbc6e448c7c0ce125c68597e2","unmapped_fields":[]},{"batch_id":"pipe-64fa630a45bef698500466ab0ed0c67932510f35","original":{"body":{"text":"Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.\n\nCurator correction 2026-10-24 (discovery audit record C3-B955-05; sources re-fetched 2026-10-24, excerpts re-located by curator GET): C3-B795-02 says the generation schema constrains output_compression with minimum 0 and maximum 100. In master openapi.yaml, CreateImageRequest says: \"The compression level (0-100%) for the generated images. This parameter is only supported for the GPT image models with the `webp` or `jpeg` output formats, and defaults to 100.\" with no minimum or maximum keys. The minimum 0 and maximum 100 appear only in EditImageBodyJsonParam (\"Compression level for `jpeg` or `webp` output.\") and the Responses ImageGenTool. The default of 100 applies to generations as well as edits.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.\n\nLimitations: The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"},{"url":"https://raw.githubusercontent.com/openai/openai-openapi/master/openapi.yaml","note":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format"}]},"tags":[],"type":"article","links":[],"title":"Which output formats, compression levels and transparent-background settings do the OpenAI image generation and edit endpoints document, and which combinations are valid?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Corrected 2026-10-24 - see C3-B955-05; the original statements below are kept for history and are superseded where the correction says so. Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. ...","evidence":{"claims":[{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"Curator correction 2026-10-24 (discovery audit record C3-B955-05; sources re-fetched 2026-10-24, excerpts re-located by curator GET): C3-B795-02 says the generation schema constrains output_compression with minimum 0 and maximum 100. In master openapi.yaml, CreateImageRequest says: \"The compression level (0-100%) for the generated images. This parameter is only supported for the GPT image models with the `webp` or `jpeg` output formats, and defaults to 100.\" with no minimum or maximum keys. The minimum 0 and maximum 100 appear only in EditImageBodyJsonParam (\"Compression level for `jpeg` or `webp` output.\") and the Responses ImageGenTool. The default of 100 applies to generations as well as edits.","locator":"curator correction paragraph in this record body (C3-B955-05)","classification":"sourced_fact"},{"url":"https://developers.openai.com/api/docs/guides/image-generation.md","claim":"SUPERSEDED IN PART 2026-10-24 by curator correction C3-B955-05 (see the correction claim above); original kept for history: Problem. Choosing format, compression and background so a generated asset keeps alpha and loads fast. Conditions. GPT image models on the Image API (generations and edits). Method. output_format is png (default), jpeg or webp. output_compression is an integer 0-100 that applies only to jpeg and webp; the openapi schema gives it a default of 100 on edits, and the generation schema constrains it with minimum 0 and maximum 100. The guide says jpeg is faster than png when latency matters. background is transparent, opaque or auto (default); transparent requires png or webp output (jpeg has no alpha). The spec says gpt-image-2.5-sunburst and -flare support opaque and transparent backgrounds, while for gpt-image-2 and gpt-image-2-2026-04-21 transparent support is 'in preview'. Failure modes. transparent with jpeg is outside the documented combination. The guide's example 'output_compression=50 will compress the image by 50%' is loose wording; the schema calls it a compression level, not a quality percentage, and does not define the scale. Limitations. The response is base64 only for GPT image models. Version/date. Fetched 2026-10-24T00:55:40Z.","locator":"Customize Image Output > Output format; Size and quality options; images generations/edits background description; output_compression (edits); Output format","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T05","T12"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":3,"topic_ids":["CAT:T05.05"],"confidence":"The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","limitations":["The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","limitations":["The spec text on transparency for gpt-image-2 ('preview') and the guide's phrase 'with either model' about the 2.5 models are reconciled here by inference that the preview caveat applies only to the older gpt-image-2 ids. Compression scale semantics are undefined in both sources. I did not generate images, so no test of alpha output was made.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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