Agent skill · creative production · wshobson
file-conversion
Convert files between formats — PDF to Word, HEIC to JPG, MP4 to MP3, CSV to JSON, EPUB to MOBI, and 999 total routes across images, video, audio, documents, data, fonts, ebooks, and archives. Free via changethisfile.com, no API key or signup. Use when the user needs a file converted to a different format.
Why this skill is useful
Adds a script for file conversion that utilizes a specific service's API and supports 999 conversion routes not commonly known.
What it needs
About 2k tokens when loaded. Last updated 2026-08-05. 38,570 stars on the source repository.
What this skill does
File Conversion (ChangeThisFile) Convert files between 999 conversion routes using the free ChangeThisFile service. No account or API key required. Conversions run server-side (FFmpeg, LibreOffice, Calibre, 7-Zip, sharp, Ghostscript); files are deleted within 24 hours. Decision order 1. If ChangeThisFile MCP tools are available (changethisfile:convertfile, changethisfile:listconversions) — use them directly. convertfile takes sourceurl OR base64content + sourceformat, plus targetformat, and returns a temporary download URL. 2. Otherwise, use the bundled script (requires network access to changethisfile.com): The script path is relative to this skill's directory. It base64-encodes the file, calls the hosted MCP endpoint over plain HTTPS, downloads the result, and writes it next to the input (or to [output-file]). 3. Remote file (you have a URL, not a local file) — skip the download/re-upload; one curl does it: The response text contains a download URL — fetch it with curl -o <output>. Discovering supported routes Ask before guessing if a conversion is exotic: Omit sourceformat for a grouped summary of all 999 routes. Limits and errors Max input: 25 MB (free path). Larger files: get a free API key (1,000 conversions/month) at https://changethisfile.com/docs/authentication and use POST /v1/convert. Rate limit: 5 conversions/minute per IP. On "Rate limit exceeded", wait 60 seconds and retry once. "Unsupported conversion: X→Y" errors list the valid targets for that source format. Download URLs expire after 1 hour — download immediately, then work with the local file. Environment notes Needs outbound HTTPS to changethisfile.com. On claude.ai, the code-execution sandbox restricts egress by default — prefer the MCP connector there, or the user can allow the domain under Settings → Capabilities. Full docs: https://changethisfile.com/docs/mcp
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills wshobson/file-conversion