Support: Base64 Encoder and Decoder

Tell us what happened. Include which page you were on and what you expected to see. Most answers go out within a business day.

Common questions

Is my text or file uploaded?

No. Encoding and decoding run in your browser on your own device. Nothing is sent to us or to anyone else, and nothing is stored.

How do I Base64 encode a string?

Choose Encode, type or paste the text, and the Base64 appears on the right. Text is encoded as UTF-8, so accented letters and emoji round-trip correctly. Press Copy to take it.

How do I decode Base64 to text?

Choose Decode and paste the Base64. If the bytes are text, they are shown; if they are a file, such as an image or a PDF, it is recognised and offered as a download, with a preview for images.

What is URL-safe Base64?

The same encoding with a hyphen for plus and an underscore for slash, and usually no padding, so it can sit in a web address or a token without being changed. Tick URL-safe alphabet to produce it; the decoder accepts both forms automatically.

How do I convert an image to Base64 for HTML or CSS?

Choose Encode, drop the image, and leave Data URI ticked. Pick An HTML img tag or CSS background-image under Give me to get a line you can paste straight into a page or a stylesheet. Keep it for small images; a large one makes the page heavier than a normal file would.

Why is Base64 bigger than the original?

Every three bytes become four characters, so the result is a third larger, and more with line breaks. It is a cost of fitting binary data into text.

Is Base64 encryption?

No. It only changes how bytes are written, and anyone can decode it instantly. Do not use it to hide passwords or personal data.

Is it free?

Yes, completely free, with no sign-up and no size limit beyond what your browser can hold.