URL Decode JSON

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Restore URL-Encoded JSON to Its Readable Form

APIs, web forms, and query strings frequently encode special characters as percent-encoded sequences, turning a clean JSON object into an unreadable mess of %7B, %22, and %3A codes. The URL Decode JSON tool on ToolWard reverses that encoding in one step, giving you back the original, human-readable JSON. Paste the encoded string, and the tool produces properly formatted JSON that you can inspect, edit, and use immediately.

What Is URL Encoding and Why Does It Affect JSON?

URL encoding (also called percent encoding) replaces characters that have special meaning in URLs with a percent sign followed by their hexadecimal byte value. Curly braces become %7B and %7D, double quotes become %22, colons become %3A, and spaces become %20 or +. When a JSON payload is passed through a URL query parameter, every one of these structural characters gets encoded, making the result nearly impossible to read by eye. This tool decodes all of those sequences back to their original characters.

Common Scenarios

Developers debugging webhook callbacks often find the payload URL-encoded in server logs. Copying that string and manually replacing every percent code is tedious and error-prone. QA engineers inspecting network requests in the browser's DevTools see URL-encoded JSON in POST bodies and query parameters that need decoding before they can be validated against a schema. Data analysts receiving encoded JSON exports from third-party platforms need a clean version to import into their processing pipelines.

How the Tool Works

Paste the encoded string into the input area. The tool applies JavaScript's decodeURIComponent() function, which handles all standard percent-encoded sequences including multi-byte UTF-8 characters. After decoding, the tool attempts to parse the result as JSON. If parsing succeeds, the output is pretty-printed with proper indentation, making nested structures easy to navigate. If the decoded string is not valid JSON, the tool still shows the decoded text and flags the parsing error so you know exactly where the structure breaks.

Double and Triple Encoding

In some systems, data passes through multiple encoding layers. A JSON string might be URL-encoded, then that encoded string is URL-encoded again before being embedded in another URL. The URL Decode JSON tool detects double encoding and offers to decode iteratively until no more percent sequences remain. This saves you from running the same decode operation multiple times and guessing whether you have reached the fully decoded form.

Pretty-Printing and Syntax Highlighting

Once decoded, the JSON output is formatted with consistent two-space indentation and optional syntax highlighting that color-codes keys, strings, numbers, booleans, and null values. This visual treatment makes it easy to scan large payloads for the specific field you are looking for, especially when the original encoded string was a single unbroken line hundreds of characters long.

Copy and Download

The decoded and formatted JSON can be copied to your clipboard with a single click or downloaded as a .json file for use in other tools. If you need the minified (compact) form instead of pretty-printed, a toggle switches between the two.

Privacy First

All decoding happens in your browser. The encoded string never leaves your device, which is essential when the JSON contains API keys, authentication tokens, personally identifiable information, or any other sensitive data you would not want transmitted to an external server.

Paste your URL-encoded string into the URL Decode JSON tool above and get clean, formatted JSON back in a heartbeat.