About this tool
Convert text to and from Base64 using browser-native APIs. Common uses: small payloads for data URLs, debugging Authorization headers, and embedded assets in development.
Whitespace in pasted Base64 is ignored on decode. For binary image encoding, use Image to Base64. For a deeper walkthrough, see the Base64 encoding for the web guide on the blog.
Input and output are not logged or transmitted.
How to use
- Choose Encode or Decode in the tabs above the editors.
- Paste plain text (Encode) or a Base64 string (Decode) into Input.
- Click the action button — it reads Encode or Decode to match the active tab.
- Copy the Output; switch tabs when you need the reverse direction.
Example
Encode a short credential string for a header experiment
Input
api-key:dev-secret
Output
YXBpLWtleTpkZXYtc2VjcmV0
Limitations
- This is text Base64 via `btoa`/`atob` — not a general binary file encoder for arbitrary byte streams.
- Encoding is not encryption; anyone can decode the result.
- URL-safe Base64 (−/_) is not the default alphabet; convert manually if your API requires it.
Related guides
1Related tools
4Frequently asked questions
What is Base64 encoding used for?
Encoding binary or text data as ASCII for data URLs, Authorization headers, email attachments, and embedding small assets in source.
How do I decode Base64?
Paste the encoded string, switch to decode mode, and copy the plaintext output. Whitespace in pasted Base64 is typically ignored.
Is the Base64 tool free?
Yes. No signup or usage limits.
Is my data uploaded?
No. Encoding and decoding run locally in your browser.
Can I encode images?
For binary images, use Image to Base64. This tool is optimized for text strings.