URL Encoder & Decoder
Percent-encode URLs or single values — round-trip verified
Free forever — no sign-up, nothing uploaded. Files never leave your device.
URL Encoder & Decoder
Percent-encode URLs or single values — round-trip verified
Drop your file here
or browse from your device
Browse filesdocument.pdf
1.2 MB
report.pdf
860 KB
100% private
Nothing is uploaded — everything runs in your browser.
Free forever
No account or payment required.
No sign-up
Open the tool and start using it right away.
Local processing
Processing time depends on your input and device.
About this tool
Percent-encode and decode URLs and query strings with live character-by-character transforms.
The BrainCoder URL Encoder & Decoder percent-encodes and decodes URL strings live in your browser, for free, with zero server round-trips. Encoding replaces unsafe characters — spaces, punctuation, and anything non-ASCII — with their %hex equivalents so a value can travel safely inside a URL. Paste your string and the result updates as you type.
Two encoding modes cover the two real jobs. Component-level encoding uses JavaScript's native encodeURIComponent, escaping everything except the unreserved characters that browsers safely allow, so it is ideal for a single query value. Whole-URL encoding uses encodeURI, which lets the structure of a full link survive — reserved characters like :, /, ?, & and = stay intact while unsafe characters are escaped. Decoding reverses percent-encoded strings back to their original form.
Everything runs entirely in your browser under the same rules your own code would use, so there is nothing to install, no signup, and no data leaving your machine. The tool also works offline once the page has loaded.
Key features
Everything you get with URL Encoder & Decoder — no premium upsell.
Live percent-encoding and decoding as you type — nothing to click
Component-level (encodeURIComponent) or whole-URL (encodeURI) encoding modes
Decode reverses percent-encoded strings with the strict component decoder
Handles full URLs, query strings, and individual characters
Supports Unicode and non-ASCII characters
100% client-side — no data leaves your browser; works offline once loaded
How to use URL Encoder & Decoder
Follow the steps below to use the tool.
- 1
Paste your URL or URL fragment
Enter the full URL, query string, or individual characters you want to encode or decode into the input area.
- 2
Choose Encode or Decode mode
The output updates live as you type — there is no button to press. Switch direction with the Encode/Decode toggle. In Encode mode, keep Component-level checked to percent-encode a single value, or uncheck it to preserve a full URL's structure (reserved characters like :, /, ?, & and = stay intact).
- 3
Copy the result
The output panel shows the result and its character count as you type. Grab the text with your own copy shortcut, or use 'Use result as input' to feed it back for a decode/encode round trip.
- 4
Verify in your application
Paste the result into your browser address bar, API request, or code editor to confirm it works as expected. Use 'Use result as input' to flip direction and check the round trip reproduces your original text.
Still free, still private — your files never leave your device.
Launch URL Encoder & DecoderFrequently asked questions
Quick answers before you launch the tool.
Related tools
Saved you searching — here are similar utilities.