Bech32 / Bech32m Encoder & Decoder
Build a checksummed Bech32 or Bech32m string from a prefix and data, or decode and validate one back to its parts — all locally in your browser, no upload, no sign-up.
What this tool does
Encode a human-readable prefix (HRP) plus a data payload into a checksummed Bech32 (BIP 173) or Bech32m (BIP 350) string, or decode and validate an existing Bech32 string back into its prefix, checksum variant, and data.
Bech32 is the encoding behind SegWit Bitcoin addresses (bc1…), Taproot
addresses, Lightning invoices (lnbc…), Nostr keys (npub… / nsec…), and many
Cosmos-ecosystem addresses. It packs bytes into a base-32 alphabet, adds a 1
separator after the prefix, and appends a 6-character BCH checksum that reliably
catches typos and altered characters.
Everything runs locally in WebAssembly. Your input is never uploaded.
Encode vs decode
- Encode (default): supply a prefix (HRP) such as
bc, a data payload, and a variant. The tool converts the bytes to 5-bit groups (BIP 173convertbits), computes the checksum, and returns the full Bech32 string. - Decode: paste a Bech32 or Bech32m string. The tool validates its structure,
case, alphabet, and checksum, then returns the detected HRP, the checksum
variant it matched, and the decoded data. The
hrpandvariantfields are ignored on decode — both are read from the string itself.
Bech32 vs Bech32m
| Variant | Checksum constant | Used by |
|---|---|---|
| Bech32 | 1 | SegWit v0 outputs — native P2WPKH / P2WSH addresses. |
| Bech32m | 0x2bc830a3 | SegWit v1+ (Taproot) addresses and newer schemes. |
Bech32m was introduced in BIP 350 to fix an insertion-weakness in the original checksum. On decode the correct variant is detected automatically.
Data formats
- hex (default): the payload is raw bytes written as hex (
751e76…, spaces and a leading0xare tolerated). Best for binary data like public-key hashes. - text: the payload is UTF-8 text. On decode, choose text only when the bytes are valid UTF-8; otherwise use hex to inspect the raw bytes.
Examples
| Input | Settings | Output |
|---|---|---|
751e76e8199196d454941c45d1b3a323f1433bd6 | encode · bc · bech32 · hex | bc1w508d6qejxtdg4y5r3zarvary0c5xw7kj7gz7z |
bc1w508d6qejxtdg4y5r3zarvary0c5xw7kj7gz7z | decode · hex | hrp: bc · variant: bech32 · data: 751e76…3bd6 |
hello | encode · test · bech32m · text | test1dpjkcmr0scqr9j |
test1dpjkcmr0scqr9j | decode · text | hrp: test · variant: bech32m · data: hello |
Tips
- The HRP is only used when encoding — on decode it is read from the string, so you can leave the prefix field blank.
- Bech32 strings must be all-lowercase or all-uppercase; a mixed-case string is rejected by design (BIP 173) because it would break the checksum guarantee.
- The alphabet deliberately excludes
1,b,i, andoto avoid visual confusion, so those characters never appear in the data part.
Frequently asked questions
Is this the same as generating a Bitcoin address?
Not quite. A full SegWit address prepends a witness-version symbol to the program before Bech32-encoding it. This tool encodes the raw data you give it under the prefix you choose, which is the underlying primitive — handy for inspecting, learning, or building the address layer yourself.
Which variant should I use — Bech32 or Bech32m?
Use Bech32 for SegWit v0 (legacy native SegWit) and Bech32m for SegWit v1+ / Taproot and other newer schemes. When decoding you don't have to choose — the correct variant is detected from the checksum and reported back to you.
Why does decoding sometimes fail with a checksum error?
A single altered, inserted, or dropped character changes the BCH checksum, so the string no longer validates. That is the whole point of Bech32: it catches typos before you send funds to a wrong address.
Can I decode a Nostr npub or a Lightning invoice?
Yes — paste it and decode. You'll get the prefix (e.g. npub or
lnbc), the variant, and the raw data bytes. Nostr keys use Bech32;
switch the data format to hex to read the 32-byte key.
Does my data leave my device?
No. The encoder/decoder is compiled to WebAssembly and runs entirely in your browser. Nothing is uploaded to a server.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool bech32-codec "751e76e8199196d454941c45d1b3a323f1433bd6"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/bech32-codec/?input=751e76e8199196d454941c45d1b3a323f1433bd6&mode=encode&hrp=bc&variant=bech32&format=hexMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.