Encode text
Input
hello
Output
aGVsbG8=
Base64 Encode/Decode (Text & File Support)
Use one screen for Base64 decode, Base64 encode, and quick conversion.
Convert text, files, and Data URLs safely in your browser.
No server upload (browser-only processing)
Data URL supported
UTF-8 text output
Conversion Tool
Switch mode (Encode / Decode / Auto Detect) and input type (Text / File) from the top.
Input data stays in your browser and is never uploaded.
Press Ctrl / Cmd + Enter to run conversion.
Examples
Decode Data URL
Input
data:text/plain;base64,44GT44KT44Gr44Gh44Gv
Output
こんにちは
How to use
- Start with Auto Detect, then enter text or choose a file.
- Switch to Encode or Decode manually when needed.
- After conversion, copy or download the result.
Encode to Base64
- Convert text or files to Base64.
- Choose output format: Base64 only or Data URL (with MIME).
Decode Base64
- Decode Base64 that includes spaces or line breaks.
- Supports URL-safe Base64 (- and _).
- Choose UTF-8 text output or binary download for decoded data.
Split Data URL
- Automatically split the data:...;base64, header and payload.
- Show MIME and Base64 payload separately with one-click copy.
FAQ
Decoded Japanese text looks garbled
Use "Display as text (UTF-8)" first. If the decoded data is binary, switch to "Treat as binary (download)".
Do you support Data URLs (data:image/...;base64,)?
Yes. The tool automatically separates the data:*;base64, header and payload, and shows the MIME type.
Are files uploaded?
No. Conversion runs entirely in your browser, and files are never uploaded.
Can I decode Base64 with line breaks?
Yes. Enable “Ignore whitespace and line breaks” to decode line-broken Base64.
Do you support Base64URL (- and _)?
Yes. Enable “Accept URL-safe Base64 (- and _)”.
Notes
- When decoded content is shown as text, UTF-8 is used. If the original data uses a different encoding, text may look garbled.
- Large files may take longer depending on browser memory limits.