Why does the JWT decoder not verify signatures?

Signature verification requires the secret key (HS256) or public key (RS256/ES256) that issued the token. Providing that key to a random web page is a bad idea. If you need signature verification, use a trusted library in your own code — jsonwebtoken (Node), pyjwt (Python), or your framework's built-in JWT support.

Is my pasted JSON / token stored anywhere?

No. Every developer tool here runs client-side using the browser's built-in APIs. Nothing you paste is sent to our servers, logged, cached or analysed. Close the tab and the input is gone from memory.

Why is there no Base64URL variant?

The Base64 tool auto-detects both standard and URL-safe variants on decode. On encode, it outputs the standard alphabet. If you specifically need URL-safe output (dashes and underscores instead of plus and slash), the JWT decoder handles that automatically for its inputs.

Developer

Everyday developer utilities that live in the browser: JSON pretty-print and validate with exact line-column error messages, JWT header and payload decoding (no signature verification, by design), Base64 round-tripping for text and binary, JSON-to-CSV export that quotes special characters correctly, and a side-by-side HTML/CSS/JS live compiler that sandboxes execution.

About developer on Dailiyo

These are the tools engineers reach for between context switches — you have a JWT to inspect, a JSON API response to read, a Base64-encoded credential to decode. The bar for a good developer tool is not features, it is being fast, correct on edge cases, and not asking you to sign in. Every tool on this page runs entirely in the browser: nothing you paste is transmitted anywhere.

The JSON formatter uses the browser's built-in JSON.parse() so its parsing exactly matches Node's, Chrome's DevTools, and every popular runtime. Errors surface with line and column numbers rather than the useless "unexpected token at position 4523". The JWT decoder splits on dots, Base64URL-decodes header and payload, and pretty-prints both — it deliberately does not verify signatures because signature verification requires the secret key and defeats the "paste and inspect" use case. Never trust unverified JWT payload for authorization decisions in production.

The HTML/CSS/JS compiler runs in a sandboxed iframe with no network permissions, so it can render any snippet without exposing your code or leaking cross-site data. It is intentionally simple — no npm packages, no source maps, no framework presets — for the case where you want to check whether "does this small snippet actually work" without opening a full IDE.

Developer tools (5)

Base64 Converter — Encode text or files to Base64 and decode them back, all in your browser.
JSON Formatter & Validator — Format, validate, minify and explore JSON with clear error messages.
JWT Decoder — Decode and inspect JSON Web Tokens (JWT) header and payload safely in the browser.
JSON to CSV Converter — Paste any JSON array of objects and get clean CSV ready to download.
HTML Code Compiler — Write HTML, CSS and JavaScript and see the live result side by side.

Frequently asked questions

Why does the JWT decoder not verify signatures?: Signature verification requires the secret key (HS256) or public key (RS256/ES256) that issued the token. Providing that key to a random web page is a bad idea. If you need signature verification, use a trusted library in your own code — jsonwebtoken (Node), pyjwt (Python), or your framework's built-in JWT support.
Is my pasted JSON / token stored anywhere?: No. Every developer tool here runs client-side using the browser's built-in APIs. Nothing you paste is sent to our servers, logged, cached or analysed. Close the tab and the input is gone from memory.
Why is there no Base64URL variant?: The Base64 tool auto-detects both standard and URL-safe variants on decode. On encode, it outputs the standard alphabet. If you specifically need URL-safe output (dashes and underscores instead of plus and slash), the JWT decoder handles that automatically for its inputs.

All developer tools on Dailiyo are hand-written and reviewed at least annually. If you spot an error or would like us to build a specific developer tool that is missing, email info@dailiyo.xyz or use the Contact page.