About the JWT Decoder
JWT Decoder is a free browser-based developer tool from Convertify. Paste a JSON Web Token to instantly decode its header and payload, plus see when it was issued and when it expires. Everything runs instantly with no file upload, no account, and no usage limit.
Frequently Asked Questions
Does this verify the JWT signature?
No — it only decodes the header and payload, which is just Base64 and doesn't require the secret key. Verifying a signature requires the issuing server's secret or public key, which this tool never asks for.
Is it safe to paste a real production token here?
The token is decoded entirely in your browser and never sent anywhere, so it's as safe as viewing it in your browser's dev tools — but as with any tool, avoid pasting tokens for systems you don't control into third-party sites unnecessarily.
Why does it say my token is invalid?
A JWT must have exactly three dot-separated Base64url-encoded parts (header.payload.signature). If a part is missing, truncated, or not valid JSON once decoded, decoding will fail with a clear error.
What do the "Issued" and "Expires" lines mean?
They read the standard `iat` (issued-at) and `exp` (expiration) claims from the payload, if present, and show whether the token has already expired based on your current system clock.
Related Tools
More From the Blog
How to Fit Endless Spreadsheet Grids onto Clean Printed Pages
Tired of endless spreadsheet grids spilling across separate pages and cutting off your columns? Learn how to convert Excel to PDF cleanly to fit your layouts.
How to Rebuild Visual Slide Layouts from Locked Documents
Struggling to update metrics in a locked pitch deck before a meeting? Learn how to convert PDF to PowerPoint privately to restore presentation control.
How to Fix Unsupported JFIF Format Errors and Image Blocks
Getting unexpected file format errors when downloading images from your browser? Read how to convert JFIF to PNG safely to restore system compatibility.
How to Restore High-Fidelity Details to Web Graphics
Need to edit a compressed web file in local software suites? Learn how to convert WebP to PNG privately to unlock full multi-layer editing control.
How to Improve Website Speed with Image Optimization
Large legacy images slowing down your website? Read our guide on how to safely convert JPG to WebP locally to optimize your page load speeds.
How to Fix Document Fragmentation and Combine Scattered Files
Struggling to manage scattered team reports? Learn how a secure, client-side merge PDF files pipeline organizes your data without risking server data leaks.
How to Fix Data Exposure Risks via Selective Page Extraction
Sharing massive multi-page documents can accidentally leak secure data. Read how to utilize split PDF pages safely to distribute targeted information sections.
How to Compress Transparent Graphics Without Losing Quality
Struggling with massive transparent image payloads? Learn how to convert PNG to WebP safely to maintain crisp edge layouts and save storage space.
How to Lock Document Layout Lines and Prevent Font Shifts
Worried that your business proposals will shift or look messy on a client's device? Read how to utilize Word to PDF workflows to lock formatting securely.