How do I encode or decode Base64?
Paste text or a file and the tool converts it to Base64, or turns Base64 back into the original bytes. The conversion happens in the page, so nothing is transmitted.
Runs entirely in your browser · no upload · no account · no watermark
- Choose Encode or Decode.
- Type text, paste Base64, or pick a file.
- Run it, then copy the result or download the bytes.
If a file is chosen, it is encoded instead of the text.
What this page can do
- Encode text or a file to Base64
- Decode standard and URL-safe Base64
- Optional data-URL prefix for embedding
- Nothing is transmitted
When to use this page
- Inlining a small image or font as a data URL.
- Decoding a Base64 field from an API response.
- Producing the URL-safe variant for a query parameter or a token.
When to use something else
- The file is large: Base64 grows data by about a third and the whole input sits in memory.
- You need confidentiality — Base64 is an encoding, not encryption.
- You need streaming or chunked processing.
How it compares with other options
The base64 and openssl CLIs stream files of any size and are scriptable; this page is limited by browser memory and is intended for small payloads. Anyone can decode the output instantly, so never use it to hide a secret. If you need a compact binary transfer, send a real file rather than a text encoding.
Where your files go
Nowhere. This page loads the code that does the work, and from then on the file you open is read by your own browser. There is no upload step, no temporary server copy and no cleanup to trust — the data never crosses the network, so there is nothing to delete afterwards. You can confirm it yourself: open your browser’s network panel while the tool runs and watch it stay quiet.
Questions about this tool
- Does Base64 encrypt my data?
- No. Base64 is a reversible encoding that maps bytes onto 64 printable characters — anyone can decode it in one step. It is for moving binary data through channels that only accept text, not for keeping anything secret. Use real encryption if the content is sensitive.
- Why did decoding give me a download instead of readable text?
- The decoded bytes were not valid UTF-8 text, which usually means the Base64 was produced from a file — an image, a zip, a PDF. Instead of replacing the unreadable characters with question marks, the page offers the exact bytes as a download so the result is byte-for-byte correct.
- How much bigger does Base64 make my data?
- About 33%, because every three bytes become four characters, plus padding. That is inherent to the format, not a quirk of this page. If size matters, send the binary file directly rather than embedding it as Base64.
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