Encoding & DecodingInstant workflow

Base64URL Encoder / Decoder

Encode and decode Base64URL payloads for JWTs, signed URLs, and web-safe tokens without standard Base64 character issues.

AI-Readable Summary

Work with JWT-style Base64URL payloads using the correct alphabet and padding rules.

Mode

Variant

Input

0 characters

Drag & drop a file to encode it

Images, PDFs, fixtures, and other binary files are handled fully client-side.

Output

Output appears instantly as you type

Auto mode decodes valid Base64 and encodes everything else.

AI Assist

Explain This

5 of 5 free AI explanations left today.

Paste text, Base64, or a file to get a short explanation of the variant, decoded content, and likely issues.

Advanced options

Remove line breaksUseful when decoding MIME or email-safe Base64 that includes wrapped lines.Add line breaks every 64 charsHelpful when generating Base64 for transports that expect wrapped output.

Encoded output format

javascript

// Text → Base64
const encoded = btoa('Hello world');

// Base64 → text
const decoded = atob('SGVsbG8gd29ybGQ=');

// Node.js / Buffer
const b64 = Buffer.from('Hello world', 'utf8').toString('base64');
const text = Buffer.from(b64, 'base64').toString('utf8');

What is this tool?

Base64URL Encoder / Decoder helps developers encode and decode Base64URL payloads used by JWTs and signed URLs. It is especially useful for decoding JWT segments, building signed URL payloads, normalizing web-safe token data.

How to use it

Paste or enter your base64url decoder input.

Adjust the mode, options, or sample values for the exact workflow you need.

Review the output, copy the result, and move back into your app or request.

Example

Input

eyJzdWIiOiJ1c2VyXzQyIn0

Output

{"sub":"user_42"}

The tool decodes the URL-safe Base64 variant commonly used in JWT headers and payloads.

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Frequently Asked Questions

Base64URL Encoder / Decoder helps developers encode and decode Base64URL payloads used by JWTs and signed URLs. It is built for common workflows like decoding JWT segments and building signed URL payloads.

Use it when you need a fast answer while debugging, building payloads, or validating output. Typical workflows include decoding JWT segments, building signed URL payloads, normalizing web-safe token data.

Yes. The tool is designed for fast, lightweight workflows without sign-up or heavy UI. Most processing happens instantly in the browser.