Encode / Decode
Convert text to and from URL encoding, Base64, or HTML entities.
Using toolbook means you agree to our Terms and Privacy Policy.
Your files stay on your device
How to use it
Pick URL, Base64, or HTML entities, choose encode or decode, and paste your text. The result appears instantly. Your text stays on your device.
Pick a format, choose encode or decode, and type or paste your text. The result updates as you type, ready to copy.
URL encoding makes text safe to put in a web address — spaces become %20, for example. Base64 turns any data into plain letters and numbers, which is how images and attachments sneak into emails and code. HTML entities turn characters like < and & into codes, so they show up as text on a web page instead of breaking it.
The swap button feeds the result back in the other direction — a handy way to check you get your original text back.
FAQ
What’s the difference between URL encoding and Base64?
URL encoding only swaps out the characters that would break a web address. Base64 turns any data at all into plain letters and numbers.
Why did decoding show an error?
The text isn’t valid for that format — for example, Base64 with missing characters, or a broken % code.
Can anyone else see my text?
No. It’s converted on your device and never sent anywhere.
How it worksFor the curious
URL encoding (percent-encoding) replaces characters that are unsafe in a URL component with % followed by their UTF-8 byte values in hex, using encodeURIComponent and decodeURIComponent.
Base64 re-encodes arbitrary bytes as 64 ASCII characters. Text is converted to UTF-8 bytes first, so non-English characters survive the round trip. Decoding requires valid, correctly padded Base64.
HTML entities are handled by the browser’s own HTML parser rather than a hand-maintained lookup table, so every named and numeric entity a real browser recognises is supported.