Convert numbers & text to Base36
Encode integers or arbitrary text in Base36 (0-9, a-z) — perfect for compact alphanumeric IDs, short URLs, and license keys.
1y2p0ij32e8e7
How to convert Base36
Base36 packs values into 0-9 + a-z. About 25% shorter than decimal for big numbers, and safe in URLs without encoding.
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Pick mode
Integer for math IDs, Text bytes when encoding raw strings.
Bytes flow through
TextEncoder/TextDecoderfor predictable UTF-8 semantics — emoji, surrogate pairs, and combining marks all encode losslessly.modeUTF-8TextEncoderlosslesslivemode · raw bytesnumber · UTF-8integer · text
loaded · UTF-8MIME · ready - 02
Choose direction
Encode goes value → base36; decode goes base36 → value.
Hash and signature operations call
crypto.subtlefrom the Web Crypto API, so output matches OpenSSL / Node bit-for-bit.dirWeb Cryptosubtledeterministiclivedir · optionsencode · liveencode · decode
options applied · livelive - 03
Paste input
Any non-negative integer or any UTF-8 string.
Options re-run instantly through
useEffect+useMemo— switching URL-safe mode or padding doesn’t re-encode from scratch.inputmemoisedoptionsinstantreactiveinput · encodednumber · ready9223372036854775807
encoded · livelossless - 04
Copy or download
Output is lowercase. Convert to uppercase yourself if needed.
Copy uses the Async Clipboard API; downloads ship via
Blobwith the appropriate MIME (text/plain,image/png, …) so external tools recognise them.exportclipboardblobMIME-correctclient-side✓ · copiedready · done✓ Copied
shipped · ready to shipsuccess
Encoding without surprises
Always UTF-8 first
Use TextEncoder / TextDecoder for bytes ↔ string conversion. btoa alone breaks on non-ASCII.
URL-safe vs standard Base64
Standard uses +, /, =; URL-safe swaps to -, _, no padding. Don’t mix them.
Hashes aren’t passwords
SHA-256 is fast; that’s good for fingerprints, bad for passwords. Use bcrypt / argon2 for credentials.
Watch padding rules
Some decoders are strict about = padding, others auto-pad. If round-trips fail at exactly 1 or 2 bytes, check padding.
Use Web Crypto for keys
Generate cryptographic keys via crypto.subtle, never Math.random. The latter is predictable.
JWT decode ≠ verify
Decoding a JWT just splits and base64-decodes. Verification needs the issuer’s public key / shared secret.
When to use Base36
Short URLs, serial numbers, license keys.
Short URLs
bit.ly-style IDs compress big sequential numbers. Output round-trips losslessly with the matching decoder — both run client-side, so end-to-end testing happens in a single tab. Encoding flows through TextEncoder for predictable UTF-8 semantics.
RFC-compliantLicense keys
Human-typeable serial numbers from random bytes. Web Crypto's subtle.digest produces output that matches OpenSSL, GPG, and Node's crypto module byte-for-byte. That makes the result trustworthy as a content fingerprint, ETag, or integrity check.
OpenSSL-matchedDB ID obfuscation
Hide sequential IDs without losing reversibility. Pairs cleanly with HMAC, JWT, and signed-URL workflows where bit-level correctness matters. The browser's crypto stack is FIPS 140-validated in Chrome and Firefox, so it's production-grade.
losslessOrder numbers
5 chars covers 60M+ unique values. Output uses canonical RFC 4648 / 7515 alphabets so curl, openssl, and any standards-compliant decoder accept it as input. URL-safe variants drop padding for tokens that travel in query strings.
byte-identicalJS toString(36)
Matches `Number(n).toString(36)` behaviour. Heavy hashing runs through useMemo so large inputs don't block typing. PBKDF2, bcrypt, and Argon2 expose configurable cost factors — tune for your threat model, not the default.
spec-gradeURL-safe
0-9, a-z — no escaping needed in URLs or filenames. Same input plus same options always yields identical bytes. That's the foundation for content-addressed storage (IPFS, Git, S3 ETags) and means the output is safe to commit to fixtures.
production-readyFrequently asked questions
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