Does this support Unicode and emoji?

Yes. Input is encoded as UTF-8 bytes first, so accented characters, non-Latin scripts and emoji all encode correctly. This avoids the classic "Invalid character" error you get from calling btoa directly on non-Latin text.

What is URL-safe Base64?

It replaces + with - and / with _ and removes trailing = padding, so the result can be placed in URLs and filenames without further escaping. It is defined in RFC 4648 and used by JWTs and many APIs.

Is my text uploaded anywhere?

No. Encoding runs entirely in your browser using built-in APIs — nothing is sent to any server.

Is Base64 encryption?

No. Base64 is encoding, not encryption — it has no key and anyone can decode it instantly. It exists to represent binary or text safely in systems that only accept ASCII, such as email, data URIs and JSON. Never use it to hide secrets.

Why is Base64 output longer than the input?

Base64 represents every 3 bytes of input as 4 ASCII characters, so the output is about 33% larger than the original. Padding with = makes the length a multiple of 4 in the standard variant.

When should I use standard vs URL-safe Base64?

Use standard Base64 for email attachments, data URIs and most file encoding. Use URL-safe Base64 when the value goes into a URL path, query string, filename, or a JWT segment, where + / and = would otherwise need percent-escaping.

How do I decode Base64 back to text?

Use the matching Base64 decoder, which reverses the process: it Base64-decodes to bytes and reads them back as UTF-8 text.

Base64 Encoder — Gera Tools

Base64 encoder

This tool converts any UTF-8 text to Base64, with an optional URL-safe variant. It’s useful for embedding text in data URIs, building API payloads, constructing JWT-style segments, or any system that only accepts ASCII. Encoding runs entirely in your browser, so it’s safe for sensitive input.

How it works

The text is first turned into UTF-8 bytes with new TextEncoder().encode(text). Those bytes are assembled into a binary string and passed to the browser’s native btoa(), which produces standard Base64. Encoding via UTF-8 bytes first (rather than calling btoa on the raw string) is what lets emoji and non-Latin characters encode without errors. When URL-safe is on, the result is post-processed: + becomes -, / becomes _, and trailing = padding is stripped — the RFC 4648 URL-safe alphabet.

Example

Input	Standard Base64	URL-safe
`Hello`	`SGVsbG8=`	`SGVsbG8`
`a+b/c`	`YStiL2M=`	`YStiL2M`
`café ☕`	`Y2Fmw6kg4piV`	`Y2Fmw6kg4piV`

Base64 grows the data by about one third (3 bytes become 4 characters), so Hello (5 bytes) becomes 8 characters before padding.

To reverse the process, use the Base64 decoder. Everything runs locally in your browser — nothing is uploaded.