Privacy Policy
Last updated: 2026-11 · Effective for fileformat.co
1. The Core Guarantee: Zero File Upload
Every byte of every file you inspect on fileformat.co is processed
entirely inside your browser's memory. Our inspector reads local
byte ranges with File.slice() / Blob.arrayBuffer()
inside a Web Worker. File content, file names, and file hashes are never transmitted to any
server — ours or anyone else's. You can disconnect from the internet after the page loads and
the inspector still works identically.
2. Network Boundary (Enforced by CSP)
The site is delivered with a strict Content-Security-Policy containing
connect-src 'self'. Your browser itself blocks any attempt
by page JavaScript to open a connection to a third-party origin. There is no Google Analytics,
no third-party pixel, no CDN analytics script — the only outbound-capable path is the same-origin
endpoint described below.
3. Anonymous Telemetry
We collect a minimal, anonymous event stream via
navigator.sendBeacon('/api/telemetry', …) — e.g.
"a file of size bucket 100MB–1GB was inspected" or "a mismatch alert fired". Event payloads are
whitelisted server-side and client-side: only aggregate fields such as file-size buckets,
detected format slugs, and coarse counters are permitted. Keys resembling filenames, paths,
content, or tokens are stripped before transmission. No IP-based profiling, no cookies, no
fingerprints, no user identifiers.
4. Waitlist Emails
If you voluntarily submit an email through the PeekFormat QuickLook waitlist, that address is sent
to our same-origin /api/waitlist endpoint and stored solely to
notify you about the launch. It is never sold, shared, or used for any other purpose. You may
request deletion at any time.
5. QA Fixtures & Downloads
All downloadable test fixtures under /fixtures/v1/ are
synthetic files generated by us in our build pipeline. They contain no personal data and are
dedicated to the public domain under
CC0 1.0.
6. HAR Sanitizer
The HAR Sanitizer tool runs entirely in-browser as well. Redaction is heuristic — it scrubs common credential shapes (tokens, cookies, JWTs, API keys) but cannot guarantee removal of every proprietary secret. Always review sanitized output before sharing it.
7. Contact
Privacy questions or deletion requests: open an issue on the project's GitHub repository.