Base64 to JSON Decoder

How to Use Base64 to JSON Decoder

1. Paste your Base64 string into the input. For JWT payloads, grab just the middle section (xxx.yyy.zzz → copy yyy). The tool strips whitespace before decoding by default.
2. Pick your indent. 2 spaces matches most style guides; 4 spaces aligns with Python/PEP-8 taste; Tab plays with .editorconfig-set editors; Minified strips all whitespace for one-line API payloads.
3. Toggle “Sort keys” if you want a diff-friendly output. Sorting recurses through nested objects; array element order is preserved (arrays are ordered by definition).
4. Watch the stats line. valid JSON · object · 5 keys means it parsed cleanly. If you see decoded OK · not valid JSON, the Base64 was fine but the resulting text isn’t JSON - maybe you meant the Base64-to-ASCII decoder.
5. Check the banner on JSON errors. When parsing fails, the output starts with // Decoded OK but JSON parse failed: <reason> and shows the raw decoded text below. The // comment line isn’t valid JSON - strip it if you copy the result.
6. Copy or download. Copy writes to clipboard; Download saves as decoded-<timestamp>.json with application/json MIME type. Keyboard shortcut: Ctrl+Enter / Cmd+Enter decodes and copies in one step.
7. Fix errors. Base64 errors name the exact bad character and its position. JSON errors include the offset from the JS engine - e.g. “Unexpected token y in JSON at position 12”.