Encoding & Number Bases
Base64 File Encoder / Decoder
Encode files to Base64 data URIs and decode Base64 strings back to files.
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What is Base64 File?
Base64 encodes binary data as ASCII text, commonly used for inline images and file transfer. This tool handles files up to browser memory limits.
How it works
We read the file as an ArrayBuffer, encode to Base64 using the FileReader API, and generate a proper data URI with MIME type. Decoding reverses the process.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.