Source
Input JSON
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Developer utility
Base64, URL & Hex Encoder / Decoder
Encode and decode Base64, URL, HTML, hex and binary text instantly.
Free toolkit with a JSON formatter, encoder/decoder, encryption utility and JWT parser.
Everything is processed locally in your browser and is never uploaded.
Result
Output
Formatted output will appear here.
Format or validate JSON to explore it as a tree.
Large containers are rendered on demand. A maximum of 500 items is shown per expanded container.
Format or validate JSON to see its structure and size.
Structural comparison
Compare two JSON documents
Whitespace and property formatting are ignored.
Add two valid JSON documents to compare them.
Local code generation
Generate models from your JSON
Types are inferred from the current parsed JSON; review generated code before using it in production.
Format or validate JSON to generate typed models.
Local conversion
JSON → CSV
Works with a top-level array of objects. Nested objects become dotted columns; arrays are kept as JSON inside a cell.
Format or validate a top-level array of objects to convert it.
Local conversion
Encoder / Decoder
Convert text between Base64, Base64URL, percent-encoded URLs, HTML entities, hex and binary, or apply ROT13 and simple text transforms. Everything is computed in your browser.
Ready — choose a transformation and start typing.
Web Crypto, locally
Encryption Utility
Create SHA-2 hashes, HMAC signatures and AES-GCM or AES-CBC ciphertext right here. AES keys are derived from your passphrase with PBKDF2 (150,000 iterations, SHA-256) plus a random salt and IV that travel with the ciphertext.
Ciphertext envelope: v1:salt:iv:data in the selected format.
Ready — choose an operation and enter your text.
Password studio
Strong password & key generator
Random values come from crypto.getRandomValues. Nothing is stored, logged or transmitted — copy what you need before leaving the page.
Choose a length and character set, then generate.
Decode and verify
JWT Parser
Decode the header, payload and signature of a JSON Web Token, inspect its registered claims, and optionally verify HS, RS, PS or ES signatures locally. Tokens are never uploaded.
Not verified
Paste a token, then choose Decode token.
Header
Payload
Registered claims
Signature
About the Encoder / Decoder
One text box converts between the encodings developers meet most often: Base64 and Base64URL, percent-encoded URLs, HTML entities, hexadecimal bytes, binary and plain text. Conversions run over UTF-8 bytes, so accents, CJK text and emoji survive a round trip — unlike tools built on the Latin-1-only btoa(). Live conversion updates the result while you type, and Swap sides applies the inverse transformation so a value can be verified in a single click.
What you can do
- Base64 and Base64URL encoding and decoding.
- URL encoding for a whole value or a single query-string component.
- HTML entity escaping and unescaping, numeric entities included.
- Hex and binary conversion driven by UTF-8 bytes.
- ROT13, UPPERCASE, lowercase, reverse and URL slug helpers.
- Escape or unescape text so it can be embedded inside a JSON string.
- Live conversion, one-click swap, copy and download.
How to use the Encoder / Decoder
- Pick a transformation in the Encoder / Decoder tab.
- Type or paste your text — with "Convert while typing" enabled the result updates as you go.
- Use Swap sides to run the reverse transformation on the result, or Copy result to reuse it elsewhere.
Keyboard shortcut: press Alt+1 to Alt+4 to move between tools, or ⌘K for the command palette.
Frequently asked questions
- Does Base64 hide or encrypt my data?
- No. Base64 is a reversible encoding that rewrites bytes as ASCII text, and anybody can decode it. Use the Encryption Utility if you need confidentiality.
- Are emoji and non-English characters supported?
- Yes. Text is converted to UTF-8 bytes before encoding and decoded back afterwards, so emoji, accented letters and CJK characters round trip correctly.
- Why does a decode operation sometimes fail?
- The input has to match the chosen transformation. Base64 decoding rejects characters outside the Base64 alphabet, hex decoding needs an even number of digits, and binary decoding needs a multiple of eight bits — each failure explains what is wrong.
More free developer tools
- JSON Formatter & Validator Format, validate, explore and analyze JSON instantly.
- Hash, HMAC & AES Encryption Utility Hash, sign and encrypt text locally with the Web Crypto API.
- JWT Decoder & Signature Verifier Decode and verify JSON Web Tokens, claims and signatures.
Every tool on this site runs entirely in your browser. Nothing you paste is uploaded, stored or logged, and no account is required.