JSON to Bencode

Bencode is the plain-text-but-binary-safe format that powers BitTorrent: every .torrent metainfo file, every tracker announce and every DHT message is bencode. When you generate torrent data programmatically, build a tracker client, or need fixtures for a peer implementation, producing correct bencode by hand is fiddly — strings need byte-length prefixes and dictionary keys must be sorted.

Convert JSON to Bencode turns a JSON document into standards-compliant bencode: integers to i<n>e, strings to <len>:<bytes>, arrays to lists, and objects to sorted dictionaries. The output can be pasted into a metainfo file or fed straight to a BitTorrent stack.

• Integers: JSON numbers become ie, exactly as BitTorrent clients expect.
• Byte strings: Strings are prefixed with their UTF-8 byte length.
• Lists: JSON arrays map onto bencode lists l...e.
• Dictionaries: Objects become d...e with byte-wise sorted keys.
• Nesting: Lists and dictionaries nest to any depth.
• Warnings: Floats and special values are flagged instead of silently mangled.
• Live output: The bencode updates with every keystroke.
• Private: All encoding happens in your browser.

1. Paste your JSON into the input pane.
2. Read the bencode — the encoded form appears instantly.
3. Check the warnings if a float or null was converted.
4. Copy or download the bencode output.

Example 1 — Torrent metainfo. A scraper builds a .torrent file: it assembles the info dictionary as JSON (name, piece length, files), converts it to bencode here, and writes the bytes to a file.

Example 2 — Tracker tests. A tracker implementer generates announce and announce-list payloads as JSON fixtures, then converts them to bencode for the test suite.

Example 3 — DHT messages. A P2P developer encodes a dictionary with transaction id, method and arguments as bencode, matching the wire format used by the DHT protocol.

Example 4 — Learning. A student studying BitTorrent pastes sample structures to see exactly how length prefixes and sorted dictionary keys look in practice.

• Correct by construction: Key sorting and length prefixes are handled for you.
• BitTorrent-compatible: Output follows the metainfo conventions clients actually parse.
• Fully typed: Numbers, strings, booleans, null and nested structures all map cleanly.
• Instant: Live encoding while you type.
• Zero upload: The conversion never leaves your browser.