Base64 Encoder / Decoder
A free, browser-based file tool. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Runs entirely in your browser — nothing is uploaded or stored.
How to use this calculator
- Paste your text or Base64 string.
- Press Encode or Decode.
How it works
Base64 represents data using 64 safe characters (A–Z, a–z, 0–9, + and /). It's used to embed images, pass data in URLs and store binary in text formats. It makes data about 33% larger and is not encryption.
Worked example
"Hello". encodes to SGVsbG8=.
Frequently asked questions
Is Base64 secure?
No — it's encoding, not encryption. Anyone can decode it.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.