How it works
How to use the Base64 Encode / Decode
Choose Encode or Decode
Encoding turns text into Base64; decoding turns Base64 back into text or a file.
Paste your data
Whitespace, data: URI prefixes and missing padding are handled automatically when decoding.
Work with files
Encode any file to Base64 or a data URI, and download decoded binary data such as images or PDFs.
Base64 vs. Base64URL
Standard Base64 uses +, / and = padding. Base64URL (used in JWTs and URLs) replaces them with - and _ and drops padding. The decoder accepts both. Text is encoded as UTF-8, so emoji and accented characters round-trip correctly.
Built for developers
Why developers use it
Private by design
Runs 100% in your browser. Nothing you paste is uploaded, logged or stored on a server.
Instant results
Output updates as you type, with precise error locations when something is wrong.
Works offline
Once loaded, the tool keeps working without a connection. Install it as an app if you like.
Free, no sign-up
No accounts, no limits, no watermarks.
FAQ
Frequently asked questions
Is Base64 encryption?
No. Base64 is an encoding that anyone can reverse. Use it to transport binary data as text, never to protect secrets.
Why is Base64 larger than the original?
Every 3 bytes become 4 characters, so encoded data is about 33% larger.
Is my data uploaded anywhere?
No. This tool runs entirely in your browser. Your input never leaves your device, is not logged, and works offline once the page has loaded.
Keep going
Related tools
- URL Encode / DecodePercent-encode and decode URLs and query strings
- Base64 EncodeEncode text or files to Base64
- Base64 DecodeDecode Base64 to text or a file
- Base32 EncodeEncode text to Base32 (RFC 4648)
- URL EncodePercent-encode text for URLs
- URL DecodeDecode percent-encoded text
- Image to Base64 ConverterConvert images to Base64 data URIs
- PNG to Base64 ConverterConvert PNG images to Base64