Text & Developer 2 min read
What Is Base64 Encoding? How to Encode, Decode and Convert Images
Base64 explained in plain English: what it is, why it adds 33% to size, when to use it, and how to encode text or images in one click.
Base64 is a way of writing binary data — such as an image or file — using only plain text characters (A–Z, a–z, 0–9, + and /). It lets data travel safely through systems built for text, like JSON, HTML, CSS and email.
Base64 is not encryption
This is the most important point: Base64 hides nothing. Anyone can decode it instantly. Never use it to protect passwords or secrets — it is only a format.
Encode and decode text
- Base64 Encoder — convert text into Base64.
- Base64 Decoder — turn Base64 back into readable text.
Base64 Encoder
Encode text to Base64 free, in your browser.
Convert images to Base64 and back
The Image to Base64 tool produces a data URI you can paste directly into HTML or CSS. Base64 to Image turns a Base64 string back into a downloadable picture.
When to use Base64 images
- Tiny icons embedded in CSS to save an HTTP request
- HTML emails where linked images may be blocked
- Passing small images through JSON APIs
When not to use it
Base64 makes data about 33% larger, and embedded images cannot be cached separately. For large images use normal files, compressed with the Image Compressor.
Frequently asked questions
Is Base64 secure?
No. It is an encoding, not encryption, and anyone can decode it.
Why does Base64 make files bigger?
It represents every 3 bytes of data as 4 text characters, so the result is about one-third larger.
Can I turn a Base64 string back into an image?
Yes. Paste it into Base64 to Image and download the picture.
