What is base-64.online?

base-64.online is a free collection of browser-based developer tools for everyday encoding, formatting, and token operations. We built it because developers constantly need to encode a string to Base64, pretty-print a JSON payload, or inspect a JWT — and most existing tools either require sign-up, send your data to a server, or are cluttered with ads that make them hard to use.

Every tool on this site runs entirely in your browser. Your data is never transmitted to any server, stored in any database, or logged anywhere. When you close the tab, your data is gone.

Our Tools

Base64 Encoder & Decoder — Convert text to Base64 and back in real-time. Supports standard Base64 (RFC 4648 §4) and URL-safe Base64 (RFC 4648 §5), with full UTF-8 and emoji support. Handles inputs up to 2 million characters.

JSON Formatter, Minifier & Converter — Format, minify, and convert JSON with instant syntax validation. Convert between JSON, YAML, and XML in real-time. Choose standard or compact formatting. Handles payloads up to 20 million characters.

JWT Decoder & Encoder — Decode, verify, and encode JSON Web Tokens. Supports all major algorithms: HMAC (HS256/384/512), RSA (RS256/384/512), RSA-PSS (PS256/384/512), ECDSA (ES256/384/512), and EdDSA (Ed25519). Keys can be provided in PEM or JWK format.

Privacy-First Approach

Privacy is not an afterthought — it is the foundation of how we build these tools. All encoding, decoding, formatting, and token operations are performed using JavaScript in your browser. We have no backend servers that process your data. There are no analytics trackers that record what you type.

This matters especially for JWT tokens and API keys, which are sensitive credentials. Unlike server-based tools, your tokens and keys never leave your device when you use our JWT decoder. Read our Privacy Policy for full details.

Who It’s For

These tools are designed for software developers, DevOps engineers, QA testers, and anyone who works with web technologies. Whether you are debugging an API response, configuring a CI/CD pipeline, or learning about JWT authentication, our tools help you get the job done quickly without compromising your data.

We also maintain a library of technical guides covering Base64 encoding, JSON formatting, JWT security, and related topics. These guides are written for developers of all experience levels and provide practical, real-world examples.

Open and Free

All tools are free to use with no registration, no rate limits, and no data collection. The site is supported by non-personalized advertisements. We believe developer tools should be accessible to everyone, regardless of budget or location.