How do I convert a file to Base64?

On the File to Base64 tab, choose any file and copy the raw Base64 string or the data: URI shown in the output panel.

How do I decode Base64 back into a file?

Switch to the Base64 to File tab, paste the Base64 or data: URI, optionally set a filename, then download the rebuilt file.

Which file types are supported?

Any type — documents, archives, spreadsheets, audio, video and more. The tool treats every file as raw bytes.

Is there a size limit?

Uploads are limited to 10 MB to keep the browser responsive, because Base64 is stored in memory and is about 33% larger than the file.

How is the file extension chosen on decode?

If the input is a full data: URI its MIME type is used to pick the extension; otherwise the tool defaults to .bin, and you can override the filename.

Are my files uploaded anywhere?

No. All encoding and decoding happen locally in your browser, so sensitive files stay on your device.

Why is my Base64 output truncated?

Only the on-screen preview is truncated for very large values; Copy and Download always return the full Base64.

Is Base64 encryption?

No. Base64 is a reversible encoding, not encryption — anyone can decode it, so never treat it as a way to protect secrets.

File to Base64

Encode Live

Encode any file to Base64 and decode Base64 back to a file.

About this tool

File to Base64 — Encode any file to Base64 and decode Base64 back to a file. Free, fast and private. Runs entirely in your browser at Quick Calci Tools.

Examples

Common scenarios for the File to Base64.

Encode any document

Upload a DOCX, ZIP, CSV, or any file to get its raw Base64 and data: URI.

UEsDBBQABgAIAAAAIQ… plus a data: URI with the detected MIME type.

Decode with the right extension

Paste a data: URI and the tool auto-detects the MIME type and file extension for download.

A downloadable file such as decoded-file.zip.

Who uses the File to Base64?

Common scenarios and audiences for this tool.

Backend developers

Wrap binary uploads as Base64 for JSON APIs and message queues.

DevOps engineers

Embed small config files or certificates as Base64 in manifests.

QA testers

Round-trip fixture files through Base64 to validate encode/decode paths.

Data engineers

Inspect and rebuild Base64-encoded blobs pulled from databases.

Students

Learn how binary data is represented as text for transport.

Frequently asked questions

Everything you need to know about the File to Base64.