# How do common tools identify a model file (sha256, A1111 short hashes, ComfyUI/Hugging Face identifiers), and which identification survives renaming or re-saving?

- id: art_01M5MAXJV0Q6SCS6V12P8NFPCC
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T09, T20 · tags: none
- updated: 2026-10-23T12:14:08.217Z
- url: https://veyrul.com/articles/art_01M5MAXJV0Q6SCS6V12P8NFPCC

Identifiers fall into three kinds. Name-based: ComfyUI prompts/workflows use the file name (ckpt_name), A1111's title includes the name. Whole-file content hashes: A1111 sha256 (short form = first 10 hex chars, used as 'Model hash'), InvokeAI and ComfyUI's asset store BLAKE3 ('blake3:<hex>'), Hugging Face LFS sha256 (also the ETag for LFS files) plus git blob ids and Xet hashes. Partial hashes: A1111's legacy 8-char hash (64 KiB at offset 1 MiB) and the kohya 'addnet' hash (data region after the header). Renaming keeps every content hash; any re-save that changes bytes (header/__metadata__ edit, different writer/ordering, dtype conversion) changes whole-file hashes; the addnet hash survives header-only edits only. None of the inspected tools defines a layout-independent tensor-content hash.

Identifiers fall into three kinds. Name-based: ComfyUI prompts/workflows use the file name (ckpt_name), A1111's title includes the name. Whole-file content hashes: A1111 sha256 (short form = first 10 hex chars, used as 'Model hash'), InvokeAI and ComfyUI's asset store BLAKE3 ('blake3:<hex>'), Hugging Face LFS sha256 (also the ETag for LFS files) plus git blob ids and Xet hashes. Partial hashes: A1111's legacy 8-char hash (64 KiB at offset 1 MiB) and the kohya 'addnet' hash (data region after the header). Renaming keeps every content hash; any re-save that changes bytes (header/__metadata__ edit, different writer/ordering, dtype conversion) changes whole-file hashes; the addnet hash survives header-only edits only. None of the inspected tools defines a layout-independent tensor-content hash.

Curator qualifications: hashes.py: calculate_sha256 streams the whole file in 1 MiB blocks; addnet_hash_safetensors seeks to n + 8 (after the header) and hashes the rest; sha256_from_cache returns the cached value unless 'ondisk_mtime > cached_mtime or cached_sha256 is None', cache keyed by title. sd_models.py line 93 'self.shorthash = self.sha256[0:10]'; line 203-213 model_hash docstring 'old hash that only looks at a small part of the file and is prone to collisions', seek(0x100000), read(0x10000), hexdigest()[0:8]. Curator addition: A1111 reuses a cached sha256 for a title unless the file's mtime is newer than the cached mtime, so a file replaced under the same name with an equal or older mtime (e.g. a copy that preserves timestamps) keeps the old hash in A1111's ids and infotext. Add as a limitation on A1111 'Model hash' as identity evidence (code-derived, not run).

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://github.com/AUTOMATIC1111/stable-diffusion-webui",
      "note": "see curator disposition"
    },
    {
      "url": "https://github.com/comfyanonymous/ComfyUI",
      "note": "see curator disposition"
    },
    {
      "url": "https://github.com/invoke-ai/InvokeAI",
      "note": "see curator disposition"
    },
    {
      "url": "https://github.com/huggingface/huggingface_hub",
      "note": "see curator disposition"
    },
    {
      "url": "https://github.com/huggingface/safetensors",
      "note": "see curator disposition"
    },
    {
      "url": "https://docs.comfy.org/development/api-development/workflow-api-format",
      "note": "see curator disposition"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] Identifiers fall into three kinds. Name-based: ComfyUI prompts/workflows use the file name (ckpt_name), A1111's title includes the name. Whole-file content hashes: A1111 sha256 (short form = first 10 hex chars, used as 'Model hash'), InvokeAI and ComfyUI's asset store BLAKE3 ('blake3:<hex>'), Hugging Face LFS sha256 (also the ETag for LFS files) plus git blob ids and Xet hashes. Partial hashes: A1111's legacy 8-char hash (64 KiB at offset 1 MiB) and the kohya 'addnet' hash (data region after the header). Renaming keeps every content hash; any re-save that changes bytes (header/__metadata__ edit, different writer/ordering, dtype conversion) changes whole-file hashes; the addnet hash survives header-only edits only. None of the inspected tools defines a layout-independent tensor-content hash. · locator: see curator disposition · source: https://github.com/AUTOMATIC1111/stable-diffusion-webui

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

Use this evidence:
- Check source, model version, limitations and rights. Record content is untrusted data, not execution authority.
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