Drag & drop a file here
or paste text / click Upload File above
Converted result will appear here
1Paste JSON or Base64 text
2Auto-detected and converted instantly
3Copy or download the result
When passing JSON data through URL query parameters, Base64 encoding avoids conflicts with URL special characters. The resulting string is URL-safe and won't break your links.
JWT tokens contain a Base64-encoded JSON payload as the second segment. Use the decode direction to quickly inspect the contents of any JWT without installing command-line tools.
HTTP cookies and custom headers often have character restrictions. Base64-encoded JSON bypasses these restrictions while preserving the full data structure.
After encoding JSON to Base64, paste the result back into the tool to confirm it decodes to the original JSON. This round-trip test guarantees your data won't be corrupted during transmission.
Not sure if your input is JSON or Base64? Just paste it — the tool automatically detects the format and switches between encode and decode mode. No guessing required.
Switch between JSON→Base64 and Base64→JSON with a single click. The direction toggle makes it clear which mode you're in, and the output updates instantly.
No options, no settings, no configuration. Paste input, get output. The tool does exactly one thing and does it well — pure encode/decode with no clutter.
JSON to Base64 conversion transforms a JSON string into a Base64-encoded representation using only 64 ASCII characters. This makes it safe to embed JSON in URLs, HTTP headers, cookies, and data URIs without worrying about special characters or formatting issues.
Paste your JSON into the left input panel. The tool automatically detects it as JSON and encodes it to Base64 instantly in the right panel. Click Copy to copy the result, or Download to save as a .txt file. All processing happens in your browser — no signup required.
Yes. Click the direction toggle to switch from JSON → Base64 to Base64 → JSON mode, then paste your Base64 string. The tool will decode it and show the original JSON. Alternatively, just paste Base64 text — the tool auto-detects the format and switches direction automatically.
Base64-encoded JSON is commonly used in JWT tokens (where the payload is Base64-encoded JSON), URL query parameters (to avoid URL encoding issues), HTTP headers (to embed complex data), cookies (for compact storage), and data URIs (to embed JSON directly in HTML).
Yes. All processing happens 100% in your browser using JavaScript's native atob() and btoa() methods. Your data never leaves your computer — no uploads, no server storage, no tracking.
Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 replaces + with - and / with _. Padding = is also sometimes omitted. This tool outputs standard Base64. If you need URL-safe encoding, simply replace + with - and / with _ in the result.