Base64 encoder / decoder
Encode text to Base64 or decode it back — UTF-8 safe, two-way live, fully offline in your browser.
Open Base64 encoder / decoder →What is the Base64 encoder / decoder?
A free, two-way Base64 tool that encodes plain text to Base64 and decodes Base64 back to text — live, as you type, with full UTF-8 support so accents and emoji survive the round trip. Everything runs in your browser, so nothing you paste is uploaded, and it keeps working offline after the first load.
How to use Base64 encoder / decoder
- Pick a side — Type or paste into the Plain text box to encode, or paste into the Base64 box to decode. Either side updates the other live.
- Use URL-safe if needed — Tick "URL-safe variant" if your Base64 will go in a URL or filename — it swaps the + and / characters and trims the padding.
- Copy the result — Click Copy above whichever box holds your output to put it on the clipboard.
- Start over — Click Reset to clear both boxes and begin a fresh conversion.
Frequently asked questions
Is my text uploaded anywhere?
No. Encoding and decoding happen entirely in your browser using built-in functions, so nothing you type or paste leaves your device.
Does it handle non-English characters and emoji?
Yes. The tool is UTF-8 safe, so accented letters, non-Latin scripts and emoji encode and decode correctly without becoming garbled.
What is the URL-safe variant?
Standard Base64 uses + and / which can break inside URLs. The URL-safe option replaces them with - and _ and drops the = padding, so the result is safe to drop into a link or filename.
Why does decoding give an error?
The Base64 box must contain valid Base64. Stray spaces, line breaks or non-Base64 characters can cause a decode error — check the text was copied in full.
Does it work offline?
Yes. After the first visit the tool is cached and runs with no internet connection.
Tips
- Use the swap button to flip the two boxes when you want the output to become your next input.
- Turn on the URL-safe variant before encoding anything you will paste into a web address or query string.
- Base64 is encoding, not encryption — anyone can decode it, so never treat it as a way to hide secrets.