Torrent Metainfo Inspector
Read a local .torrent file as strict bencode and inspect its file layout, v1 piece count, v2 piece-layer roots, trackers and the SHA-1 or SHA-256 info hash of the original encoded info dictionary. Add an edited copy to see whether the exact info bytes changed. The inspector does not connect to trackers, download content, or verify the actual payload files. It rejects malformed and oversized metainfo before presenting an info hash.
Key features
- Parse canonical bencode and reject unsorted or duplicate keys, invalid integers and truncated values
- Calculate v1 SHA-1 and v2 SHA-256 from the exact encoded info bytes
- Check v1 piece hash count against the declared file sizes and piece length
- Check v2 piece-layer lengths and Merkle roots for files larger than a piece
- Compare tracker-only edits with changes inside info and export a review report
How to use
- Select an original local .torrent file, or load either sample pair.
- Optionally select a modified .torrent file to compare with the original.
- Run Inspect and review the version, file sizes, piece checks, trackers and exact info hashes.
- For a comparison, check whether info bytes changed; a tracker or comment edit can keep the hash.
- Download the JSON report if you need to keep the inspection result.
Use cases
- Confirm whether a tracker URL change leaves the torrent identity intact
- Inspect a received .torrent before opening it in a client
- Check a small v1 fixture's multi-file sizes and number of piece hashes
- Catch a damaged v2 piece layer without downloading payload data
Frequently asked questions
Does an unchanged info hash mean the download is safe?
No. The hash identifies encoded info metadata. It does not authenticate the publisher, scan content or verify downloaded file bytes. SHA-1 also has collision limitations; compare the exact info-byte result when reviewing edits.
Why can a tracker edit leave the info hash unchanged?
The tracker is a top-level metainfo field outside the info dictionary. BEP 3 and BEP 52 hash only the exact encoded info dictionary, so edits outside it can preserve the info hash.
What v2 data is checked?
The full SHA-256 info hash is calculated and piece-layer Merkle roots are checked for files larger than one piece. A single-piece file's pieces root cannot be checked without its actual content. Hybrid v1/v2 file ordering and padding equivalence are not proven here.
Will this tool contact a tracker or download anything?
No. Tracker URLs are displayed as inert text. The inspector neither joins a swarm nor checks whether any listed payload file exists.
What are the limits?
Each .torrent file is limited to 4 MiB, 100,000 parsed nodes, 32 nested levels, 5,000 listed files and 256 distinct trackers. File paths are display-only and suspicious traversal components are flagged.
Privacy
The selected .torrent bytes stay in this browser tab. This tool does not fetch tracker URLs, join peers or send metainfo to the site. A JSON report is downloaded only when requested; it includes names, tracker URLs and hashes, so review it before sharing.
Comments & questions