Text tool

Base64, both directions.

Text or files, encode or decode, with URL-safe output and proper UTF-8 handling — the part most online converters get wrong.

Free, no sign-up
Nothing is uploaded
No watermark, no limits

Base64 encoder and decoder

Free

Input

URL-safe output (- and _ instead of + and /, no padding)

Output

Output appears here.

File to data URI

Runs entirely in your browser. Nothing is uploaded.

Worth knowing

How to get this right.

01

Base64 is encoding, not encryption
Anyone can decode it in one step — this page does it instantly. It exists to move binary data safely through channels that only handle text, such as email bodies, JSON fields and data URIs. Never treat a Base64 string as a way of hiding anything.
02

UTF-8 is where most converters break
The browser's btoa only accepts Latin-1, so any accent, emoji or non-Latin character throws. This tool converts to UTF-8 bytes first, which is why café and 日本語 round-trip correctly here and produce garbage in a lot of other online tools.
03

It costs you a third in size
Base64 turns every three bytes into four characters, so expect roughly 33% growth. That is why inlining a large image as a data URI is usually a bad trade — you save one request and pay for it on every page load, uncached.

Questions

About this tool.

Is Base64 secure?

No, not at all. It is trivially reversible and provides no protection whatsoever. If something needs to be secret, it needs encryption.

When should I use URL-safe Base64?

When the string goes into a URL path, query parameter or filename. Standard Base64 uses + and /, which have meaning in a URL, and = padding often gets mangled. The URL-safe variant replaces them.

What is a data URI?

A file encoded directly into a URL, so it needs no separate request. Useful for small icons in CSS. The file option above produces one, complete with the correct MIME type.

Why is there a 2 MB limit on files?

Because the resulting string is about a third larger again, and rendering a many-megabyte string into the page will freeze the tab. For anything larger, host the file properly.

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