Encode JSON to Base64
Encode a JSON object to Base64 for headers, query strings and config values. Paste JSON and copy the encoded string. Free and local.
Part of the free Base64 Encoder. Runs in your browser — nothing is uploaded.
Encode JSON to Base64
Some systems expect JSON passed as a single Base64 string, for example in HTTP headers, environment variables and message attributes. Minify your JSON first, then encode it for the smallest result.
Worked example: A compact JSON object
JSON
{"userId":42,"role":"admin"}Base64
eyJ1c2VySWQiOjQyLCJyb2xlIjoiYWRtaW4ifQ==
Practical tip
Minify JSON before encoding. Whitespace adds bytes, and Base64 makes every byte count by 33%.
How to use this Base64 Encoder
- 1Use the live tool above — it runs entirely in your browser and never uploads your data.
- 2Paste the sample from the worked example, or use your own input.
- 3Copy the result, then adapt the same steps in your editor, script, or pipeline.
Encode JSON to Base64 FAQs
How do I decode the Base64 back to JSON?
Use the Base64 decoder, then paste the result into a JSON formatter to make it readable again.
Should I put secrets in Base64-encoded JSON?
No. Base64 hides nothing. Anyone can decode it, so encrypt sensitive data separately.
More Base64 Encoder pages
- Encode a String to Base64Encode any text string to Base64 online. Paste your text and copy the result instantly. Supports UTF-8, free and processed in your browser.
- Base64 Encode UTF-8 Text and EmojiEncode Unicode text, accents and emoji to Base64 correctly. Avoid the btoa "Invalid character" error by encoding as UTF-8 first.
- Base64URL Encoder (URL-Safe Base64)Encode text to URL-safe Base64 (Base64URL) with - and _ instead of + and /, and no padding. The format used in JWTs and URLs.
- HTTP Basic Auth Header GeneratorGenerate an HTTP Basic Authorization header by Base64-encoding username:password. Build the header for curl, fetch and Postman.
- Base64 Encode in JavaScriptEncode a string to Base64 in JavaScript with btoa() in the browser or Buffer in Node.js. Check your result with the encoder before shipping.
- Base64 Encode a URLBase64 encode a URL to pass it safely as a parameter, hide it from casual reading or store it in a single token. Use Base64URL for safer links.
- Base64 MIME Encoding With 76-Character LinesMIME Base64 wraps lines at 76 characters. See what wrapped output looks like for email attachments and PEM-style data.
- Base64 Encode in PythonEncode a string to Base64 in Python with base64.b64encode. Remember to encode to bytes first and decode the result. Verify with the online encoder.
- Base64 Encoding Without PaddingEncode to Base64 without = padding characters. See when padding is optional, how to add it back, and why JWTs omit it.