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.

What is the Base64 Encoder?

Free Base64 encoder that turns any UTF-8 text into Base64, with an optional URL-safe variant. Runs entirely in your browser — nothing is uploaded. It runs free in your browser on Gera Tools, with nothing uploaded.

Base64 Encoder — Gera Tools

Name: Base64 Encoder
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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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.

Standard vs URL-safe: when each matters

Scenario	Use standard Base64	Use URL-safe Base64
Email MIME attachments	Yes	No
HTML data URI (`src="data:..."`)	Yes	No
JWT header and payload	No	Yes
Query-string parameter	No	Yes
File name or path segment	No	Yes
HTTP cookie value	No	Yes (safest)

Standard Base64 uses + and /, which have special meaning in URLs and query strings — + decodes as a space and / is a path separator. URL-safe Base64 swaps those for - and _, making the result safe to drop directly into a URL without percent-encoding. Padding (=) can also interfere with some URL parsers, which is why URL-safe Base64 typically omits it.

Common encoding mistakes to avoid

Encoding non-Latin text directly through btoa: Calling btoa("café") in JavaScript throws a DOMException because the French character é has a code point above 255. This tool encodes via UTF-8 bytes first, which is the correct approach and handles emoji and any non-ASCII script cleanly.

Treating Base64 as encryption: Base64 is encoding, not encryption. Anyone who can see the Base64 string can decode it instantly — it provides no confidentiality. Use it to represent binary data safely in text contexts, not to hide content.

Double-encoding: If you paste already-Base64-encoded text into this encoder, you get double-encoded output. Make sure you are starting from the original plaintext, not from an existing Base64 string.