URL Encoder / Decoder — Percent-Encoding, Free

About the URL Encoder / Decoder Tool

Most online URL encoders either upload your text to a server, limit the input size, or silently corrupt non-ASCII characters. This one runs entirely in your browser, preserves surrogates, and gives you full control over how percent‑encoding works. Type or paste any text, click Encode to produce a URL‑safe string, or click Decode to reverse it. The result copies to your clipboard or downloads as a .txt file, and edge‑case settings let you preserve safe characters (– _.~) or keep surrogate pairs intact.

Place‑formats differ in how they count characters: a meta description is truncated on pixels, a tweet counts a link as 23 regardless of real length, and a server‑side encoder may silently drop characters you need. Knowing exactly what your tool produces — and having the bytes to prove it — is the only way to hit a length limit deliberately instead of guessing and cutting something you needed.

How to use the URL Encoder / Decoder Tool

Paste or type the text you want to encode or decode into the box.
Click Encode to produce a URL‑safe percent‑encoded string, or click Decode to reverse percent‑encoding.
Use the Settings dialog to preserve safe characters (– _.~) or keep surrogate pairs if you are working with emoji or CJK.
Copy the result to your clipboard or download it as a .txt file.

What this tool encodes and decodes

Input	Output	Notes
Hello World	Hello%20World	Space becomes %20
Hello%20World	Hello World	Valid %XX decodes back
😀 (emoji)	%F0%9F%98%80	Emoji encoded as 4‑byte UTF‑8 sequence
CJK: 中文	%E4%B8%AD%E6%96%87	Chinese characters encoded as UTF‑8 %XX
Bare % sign	%25	Percent sign is encoded
already %20 encoded	already%20encoded	Valid %XX preserved on encode (not double‑encoded)

Keyword density normalises each word to lowercase and strips anything that is not a-z or 0-9, so "Word," "word" and "WORD" are the same keyword — and so is "café" and "cafe".

Frequently asked questions

Does this tool send my text to a server?

No. All encoding and decoding happens entirely in your browser using JavaScript. Your text never leaves your machine.

What characters are safe and never encoded?

By default, alphanumeric characters (A–Z, a–z, 0–9) and – _.~ are never encoded. You can toggle this in Settings if you need different behaviour.

How are emoji and CJK characters handled?

Code points above 0xFFFF (astral characters) are encoded as surrogate pairs (%XX per unit). Decode reconstructs the original character. Enable “Preserve surrogate pairs” in Settings to keep them as‑is instead.

What happens to a bare % sign?

A percent sign not followed by two hex digits survives encode as‑is and is left as‑is during decode, marked as “unresolved %”.

Can I encode an already‑encoded string without double‑encoding it?

The engine preserves already‑valid %XX sequences on encode, so they pass through unchanged. Decode will convert them back to the original character.

Guides

URL Encoder/Decoder Guide: Encode & Decode Percent-Encoding
Guide to encoding and decoding URL percent-encoding. Encode text to a URL-safe string or decode percent-encoded strings, entirely in your browser with no uploads.
How to Compare Two Texts Online: Diff Without Uploading
Learn how to compare two texts online. A line-by-line diff shows every added, removed and unchanged line, side by side or unified, with nothing uploaded to a server.
Why Is Your Typing Test Score Off? The Fixed-Sample Method
Most free typing tests show a single WPM number and stop there. This guide explains the three WPM definitions, why a random sample makes two runs uncomparable, and how to read your own result card.