JWT Decoder

Decode JSON Web Tokens locally to view header and payload.

🌐 Uses API

Also try:Historical Age Calculator·Pet Age Calculator·Relationship Timeline

Header

Payload

Note: Signature is not validated. This tool only decodes locally in your browser.

Frequently asked questions

Is verification performed?

No. This tool only decodes Base64URL parts and displays JSON.

Does it send my token to a server?

No. All decoding happens locally in your browser.

Why do I see errors decoding?

Ensure the JWT has three segments separated by dots and is not truncated.

Related tools

Privacy

Most processing happens locally in your browser for speed & privacy. Network calls occur only for live rates or updates.

Premium

Premium feature

Historical analysis & trends

Track your past calculations and visualize patterns.

Calculation presets

Save, load, and manage your favorite calculation setups.

Import

No presets saved yet.

Scenario planning

Compare multiple inputs side-by-side.

Batch processing

Upload a CSV to compute results in bulk.

Custom formulas

Create and reuse your own rules.

External data

Connect Google Sheets or an API as inputs.

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