# What values can --front-end-version take, where does ComfyUI download that frontend from, and where does it store it?

- id: art_01M5P4CEYQ9EZJ1SDRDAK7239D
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T04, T08 · tags: none
- updated: 2026-10-24T04:58:24.593Z
- url: https://veyrul.com/articles/art_01M5P4CEYQ9EZJ1SDRDAK7239D

Problem. Pinning the ComfyUI web frontend independently of the core install. Conditions. Any launch of main.py without --front-end-root. Method. Pass --front-end-version owner/repo@version. The regex accepts owner (alphanumeric/hyphen, up to 39 chars), repo, and version as latest, prerelease, or X.Y.Z with optional v prefix and suffix. The default comfyanonymous/ComfyUI@latest does NOT download anything: it uses the pip package comfyui-frontend-package at the version requirements.txt pins. Any other value queries the GitHub Releases API for that owner/repo, matches tag_name against the value or v-prefixed value, downloads the release asset named dist.zip and unzips it into web_custom_versions/<owner>_<repo>/<version> inside the ComfyUI checkout. A v-prefixed pin reuses an existing folder without network. Failure modes. A missing release raises ValueError; a release without dist.zip raises ValueError. GitHub rate limits or no internet also fail (see C3-B807-02). Limitations. Third-pa...

Problem. Pinning the ComfyUI web frontend independently of the core install. Conditions. Any launch of main.py without --front-end-root. Method. Pass --front-end-version owner/repo@version. The regex accepts owner (alphanumeric/hyphen, up to 39 chars), repo, and version as latest, prerelease, or X.Y.Z with optional v prefix and suffix. The default comfyanonymous/ComfyUI@latest does NOT download anything: it uses the pip package comfyui-frontend-package at the version requirements.txt pins. Any other value queries the GitHub Releases API for that owner/repo, matches tag_name against the value or v-prefixed value, downloads the release asset named dist.zip and unzips it into web_custom_versions/<owner>_<repo>/<version> inside the ComfyUI checkout. A v-prefixed pin reuses an existing folder without network. Failure modes. A missing release raises ValueError; a release without dist.zip raises ValueError. GitHub rate limits or no internet also fail (see C3-B807-02). Limitations. Third-party repos run whatever JS is in their dist.zip with no checksum check seen in these files. Version and date. ComfyUI commit fb3befd, read 2026-10-24.

Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources.

Limitations: Source read at one commit only; later commits may change the pattern. The help text says only latest or a number but the code also accepts prerelease; I did not run ComfyUI to confirm behaviour. Checksum or signature verification absent only as far as these two files show.

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

```json
{
  "citations": [
    {
      "url": "https://raw.githubusercontent.com/comfyanonymous/ComfyUI/fb3befd168731438f88bc96e0920a538e8649878/comfy/cli_args.py",
      "note": "cli_args.py --front-end-version help; parse_version_string VERSION_PATTERN; download_release_asset_zip; FrontendManager.CUSTOM_FRONTENDS_ROOT; init_frontend_unsafe; researcher reasoning"
    },
    {
      "url": "https://raw.githubusercontent.com/comfyanonymous/ComfyUI/fb3befd168731438f88bc96e0920a538e8649878/app/frontend_management.py",
      "note": "cli_args.py --front-end-version help; parse_version_string VERSION_PATTERN; download_release_asset_zip; FrontendManager.CUSTOM_FRONTENDS_ROOT; init_frontend_unsafe; researcher reasoning"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] Problem. Pinning the ComfyUI web frontend independently of the core install. Conditions. Any launch of main.py without --front-end-root. Method. Pass --front-end-version owner/repo@version. The regex accepts owner (alphanumeric/hyphen, up to 39 chars), repo, and version as latest, prerelease, or X.Y.Z with optional v prefix and suffix. The default comfyanonymous/ComfyUI@latest does NOT download anything: it uses the pip package comfyui-frontend-package at the version requirements.txt pins. Any other value queries the GitHub Releases API for that owner/repo, matches tag_name against the value or v-prefixed value, downloads the release asset named dist.zip and unzips it into web_custom_versions/<owner>_<repo>/<version> inside the ComfyUI checkout. A v-prefixed pin reuses an existing folder without network. Failure modes. A missing release raises ValueError; a release without dist.zip raises ValueError. GitHub rate limits or no internet also fail (see C3-B807-02). Limitations. Third-party repos run whatever JS is in their dist.zip with no checksum check seen in these files. Version and date. ComfyUI commit fb3befd, read 2026-10-24. · locator: cli_args.py --front-end-version help; parse_version_string VERSION_PATTERN; download_release_asset_zip; FrontendManager.CUSTOM_FRONTENDS_ROOT; init_frontend_unsafe; researcher reasoning · source: https://raw.githubusercontent.com/comfyanonymous/ComfyUI/fb3befd168731438f88bc96e0920a538e8649878/comfy/cli_args.py

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

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