We do not store your data. All processing happens in your browser.

Static + Browser-Only

Mask JWT Payloads Online

Paste a JWT token and mask sensitive claims in your browser before sharing it with AI tools, tickets, chats, or documentation.

All processing happens locally in your browser. No server processing required.

Input

Raw JWT token

Tip: paste text or drag and drop a file here.

Paste or drag and drop a file, then run the tool.

Output

Masked JWT

Masked payload will appear here

Use Cases

Why use a JWT masking tool?

Use this tool when JWTs need to be shared for debugging or support without exposing raw claims, identifiers, emails, phone numbers, or tenant-specific references first.

  • Decode and mask sensitive JWT claims before sharing tokens externally
  • Redact emails, phone numbers, IDs, secrets, and custom claim names
  • Keep masking local to the browser instead of sending tokens to a backend
  • Useful for support, debugging, QA, and vendor communication

Masking Logic

How to mask sensitive values in JWTs

Mask Payload decodes the JWT header and payload locally in the browser, masks common sensitive claim names, then rebuilds a masked token string for safer sharing.

  • Local JWT header and payload decoding
  • Field-based masking for sensitive claims and custom keys
  • Readable output with a masked token plus decoded masked payload

Privacy Detail

Does this JWT masking tool upload data?

This tool runs as a static browser page. It decodes and masks JWT data in client-side JavaScript in the current tab. No form submission, fetch request, XMLHttpRequest, or masking API call is used during the masking flow.

  • No form submission is used for the masking flow.
  • No fetch, XMLHttpRequest, or API call runs during masking.
  • The page uses local base64url decoding and JavaScript parsing in the current tab.
  • The token is only written back to the output field unless you copy or download it yourself.
  • The masking flow does not store the payload in browser local storage.

FAQ

Who should use a JWT sanitizer?

Does this tool upload JWTs anywhere?

No. The masking runs entirely in the browser on the current page.

Can I add custom masking fields?

Yes. Add custom field names such as tenantId, caseNumber, or vendorRef and mask again.

Who is this tool for?

Mask Payload is for engineers, support teams, API reviewers, and anyone who needs to share JWT examples more safely.

Why JWT masking matters before sharing tokens

JWTs are easy to paste into tickets, docs, and support threads because they look compact, but their payloads can still contain personal data, customer identifiers, tenant references, or internal claim names that should not be shared in raw form.

A browser-based JWT masker helps teams decode, review, and sanitize token contents first while keeping the debugging workflow local to the current tab.

Examples

Example input and output

These short examples show the kind of input this page is built for and the kind of cleaned result you can expect before sharing data externally.

Example Input Sample data before masking or extraction 
eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6ImpvaG4uZG9lQGV4YW1wbGUuY29tIiwidG9rZW4iOiJza19kZW1vIn0.signature
Example Output Sanitized or extracted result 
{"email":"****","token":"****"}

Tool Directory

Browse masking tools by category

Find related browser-only masking tools for structured payloads, requests, tokens, config files, logs, infrastructure secrets, web payloads, security review, and practical guides.