YL
YoussefLabs

Base64 Encoder / Decoder

Developer Utilities

Encode text to Base64 or decode Base64 back to text in your browser. Unicode-safe, so Arabic, Greek, and emoji work.

Local browser processing0 network transfers
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Key Capabilities

Runs Locally

Encoding and decoding happen in your browser. Tokens, credentials, and payloads are never uploaded.

True Unicode Support

Text is converted as UTF-8 bytes, so Arabic, Greek, CJK, and emoji round-trip correctly.

Honest Error Messages

Invalid characters, bad padding, and bytes that are not valid UTF-8 are explained, never silently garbled.

Copy and Keyboard Shortcuts

Copy the result in one click, or press Ctrl+Enter (Cmd+Enter on Mac) to convert.

100% Client-Side Processing

When you use Base64 Encoder / Decoder, your data never leaves your browser. All transformations execute in-memory on your local machine with zero server uploads. Web assets are downloaded to run the tool, but your input data is never transmitted.

Frequently Asked Questions

Is my text sent to a server?

No. Encoding and decoding run entirely in your browser. Nothing you type is uploaded or stored. The page does download the code needed to run the tool.

Why does decoding sometimes say the bytes are not valid UTF-8?

This tool decodes Base64 into text. If the Base64 holds binary data (an image, a compressed file) or text in another encoding, the bytes are not valid UTF-8 text, so an error is shown instead of unreadable characters.

Does it support Base64URL?

Not in this version. It handles standard Base64 (A-Z, a-z, 0-9, +, / and optional = padding). If the input uses - and _ instead, the tool tells you it looks like Base64URL.

Is Base64 a way to hide or encrypt data?

No. Base64 is an encoding that anyone can reverse, not encryption. Do not use it to protect secrets.