Skip to content

Encoding tools

Encoding tools translate between binary or special-character data and text-safe formats. The three most-asked are Base64 (binary to ASCII), URL encoding (special characters to %xx escapes), and JWT decoding (parsing JSON Web Tokens to inspect their claims). Each comes up in everyday API and web work — enough to want a fast, browser- local tool that doesn't send the data to a server you didn't choose.

The Base64 encoder/decoder goes both directions, with a toggle for the URL-safe variant (which uses - and _ instead of + and / for safe inclusion in URLs). Useful for embedding small images as data URIs, decoding email attachments, and inspecting the body of HTTP basic-auth headers. The URL encoder/decoder applies the percent-encoding scheme defined by RFC 3986, with options for component vs full URI encoding (spaces become %20 vs +; the difference matters for query strings vs path segments).

The JWT decoder parses the three base64-encoded sections of a JSON Web Token (header, payload, signature) and pretty-prints the JSON, with the registered claims (iss, sub, aud, exp, nbf, iat, jti) translated to human-readable timestamps. Critical: the decoder does NOT verify the signature, which requires the issuer's public key. This tool is for inspection only; if you need verification, use a server- side library with the appropriate key.

Tools in this category

Encode

  • URL Encoder / Decoder

    Encode text to a percent-encoded URL component or whole URL, or decode percent-encoded strings back to readable text.

  • JWT Decoder

    Decode JWT header, payload, and standard claims — never sent to a server, no signature verification.

  • QR Code Generator

    Generate QR codes for any URL or text — color and size options, PNG and SVG download.