Developers
Base64 Encoder
Text to Base64 and back — with UTF-8 handled properly, emojis included.
An API token to inspect, an HTTP header value to decode, a string to embed in a URL or a JSON payload: Base64 shows up everywhere in a developer’s day. This tool encodes and decodes live, in both directions, with proper UTF-8 handling: accented characters, symbols and emojis come out intact — unlike the browser’s raw btoa() function, which chokes on anything beyond ASCII. Paste your text, watch the result appear as you type, and copy it with one click. Everything runs locally in your browser, so tokens and payloads never reach a server. Free, no sign-up, no usage limits of any kind.
How does it work?
- Paste your plain text or Base64 string into the input area.
- Click “Encode” or “Decode” depending on the direction you need.
- The result appears instantly in the output area.
- Copy it with one click.
Frequently asked questions
Why do accented characters come out garbled?
Because the string was encoded or decoded as Latin-1 instead of UTF-8 — the historic flaw of JavaScript’s btoa() and atob(). This tool uses TextEncoder/TextDecoder, so “é”, “ü” or an emoji are encoded as UTF-8 bytes and restored exactly as they went in.
Is Base64 encryption?
No, and the confusion is dangerous: Base64 is plain encoding, reversible by anyone in a second — this very tool proves it. It protects nothing. To keep a secret confidential you need real encryption (AES, for instance), never Base64 on its own.
Why is the encoded string longer than the original?
Base64 represents every 3 bytes with 4 characters, so the output is roughly 33% larger than the input, plus optional “=” padding at the end. That is the price of carrying binary data through formats that only accept text.
What is the difference between Base64 and Base64URL?
Standard Base64 uses “+” and “/”, which clash with URL syntax. The Base64URL variant swaps them for “-” and “_” and usually drops the “=” padding. It is the flavour used by JWTs and most tokens passed as URL parameters.