Base64 Encoder / Decoder
Encode text or files to Base64, or decode Base64 back to text. Everything happens locally.
Encode plain text or any uploaded file into a Base64 string, or paste a Base64 string to decode it back to readable text or a downloadable file. Base64 is commonly used to embed binary data (images, fonts, certificates) inside JSON, CSS, or email payloads as plain ASCII text. Both directions run entirely in your browser, so there's no upload and no practical size limit beyond your device's memory.
Runs on your device. This tool processes your file inside this browser tab. Nothing is uploaded, so it also works offline once the page has loaded, and closing the tab discards the file from memory.
Loading tool
How it works
- 01
Paste text, or upload a file to encode.
- 02
Switch between Encode and Decode mode as needed.
- 03
Copy or download the result.
Details
- Category
- Developer & data
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-12
Common questions
Can I encode files, not just text?
Yes - upload a file and it's encoded to a Base64 string you can copy or download.
Why does decoding sometimes fail?
The input must be valid Base64 (correct alphabet and padding). Extra whitespace or truncated strings will throw an error.
Does Base64 encoding compress data?
No - it actually increases size by about 33%, since it re-encodes binary data as ASCII text.
Is my data uploaded anywhere?
No - encoding and decoding both run locally.
Use this from your code
This tool is also a REST endpoint, so you can run it in a pipeline instead of by hand. It is free and needs no API key. See the API reference for every parameter.
curl -X POST https://fileoven.com/api/v1/tools/base64 \
-H "Content-Type: application/json" \
-d '{"text":"hello world","mode":"encode"}'