Base64 Encoder / Decoder

Encode text or files to Base64, or decode Base64 back to original content. 100% client-side — nothing leaves your browser.

Paste or type your text here

or

What is Text/File to Base64 Conversion?

Base64 encoding converts binary data or text into ASCII text format. FreeCVT encodes and decodes entirely in your browser.

Understanding the Formats

Text/File Format

Base64 is a binary-to-text encoding scheme using 64 ASCII characters.

Base64 Format

The encoded output is a string of A-Z, a-z, 0-9, +, and / characters.

When to Use This Converter

  • Embed images in HTML or CSS as data URIs
  • Encode files for email transmission
  • Decode Base64 strings from APIs

Limitations

  • Base64 encoding increases file size by approximately 33%
  • Very large files may be slow to process
  • Binary files may not display as text after decoding

Why Freecvt?

100% Private

Everything is processed in your browser. Nothing is uploaded to any server.

Instant

Encoding and decoding happens instantly. No waiting for uploads or processing.

Works Everywhere

Runs on any device with a modern browser. No installation required.

Frequently Asked Questions

What is Base64 used for?

Embedding images in code, transmitting binary data over text protocols.

How much larger is Base64?

Approximately 33% larger than the original.

Can I decode any Base64 string?

Yes, if it is valid Base64 format.

Is my data uploaded?

No. Everything happens in your browser.