Base64 Encoder & Decoder for Files

Base64 Tool

Input

Output

URL-safe mode MIME line breaks (76 chars)

Input: 0 B

Output: 0 B

Ratio: --

Select a file to encode (max 10 MB)

Include data:mime;base64, prefix

Base64 Output

Upload an image

Include data:image/...;base64, prefix

Base64 Data URI

Paste Base64 string

Filename

File Type

Local Base64 Inspector

Format Waiting for input

Decoded Size --

Padding --

Share Risk --

Paste or generate Base64 to inspect alphabet, padding, size and share-safety hints locally.

What is Base64?

How it works: Base64 encodes binary data into ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). Output is ~33% larger than input.

Common uses:

• Embedding images in HTML/CSS

• Email attachments (MIME)

• Data URIs

• JWT tokens

URL-Safe Mode

Standard Base64 uses + and / which are special in URLs. URL-safe mode replaces them:

            + → -
/ → _
= (padding) removed
          

Security Note

Disclaimer: Base64 is encoding, not encryption. Anyone can decode it. Never use Base64 to protect passwords, tokens, or sensitive data. It is not an official file-authenticity or security check.

All conversion processing happens in your browser after the page loads. Base64 is reversible, so treat encoded tokens and private records as exposed.

Reference: RFC 4648 Base-N Encodings, including standard and URL-safe Base64 alphabets.

Keyboard Shortcut

Ctrl+Enter — Swap encode/decode

Ctrl+Shift+C — Copy output

Frequently Asked Questions

Can I encode files to Base64?

Yes. AfroTools Base64 tool has dedicated File Upload and Image to Base64 tabs where you can drag and drop or select any file to encode. You can optionally include the data:mime;base64 prefix for use in HTML/CSS, and download the Base64 output as a .txt file.

Is there a file size limit for Base64 encoding?

Yes, the file upload limit is 10MB. Since Base64 encoding increases data size by approximately 33%, the output will be larger than the original file. Text encoding and decoding have no practical limit beyond your browser's memory.

Is my data secure when using the Base64 encoder?

Yes. All encoding and decoding happens in your browser after the page loads. Important: Base64 is an encoding format, not encryption. It should not be used to protect sensitive data, and encoded secrets remain easy to decode.

Does the tool support URL-safe Base64 encoding?

Yes. Toggle the URL-safe mode checkbox to use URL-safe Base64, which replaces + with -, / with _, and removes padding = characters. This is useful when embedding Base64 data in URLs or filenames.

What is the difference between Base64 and encryption?

Base64 is an encoding scheme that converts binary data to ASCII text. It is not encryption and provides no security. Anyone with a Base64 string can decode it instantly. For security, use proper encryption algorithms like AES or RSA.

Base64 Encoder & Decoder

Convert locally, then confirm what the encoded data exposes

Result and export

Privacy and limits

Frequently Asked Questions