Base64 Encoder / Decoder
Encodes text to Base64 and decodes Base64 back to plain text in the browser.
Designed to process your files locally in your browser. Zerdly does not intentionally upload or store them unless this page says otherwise.
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=.
Common mistakes
- Pasting a data URL and expecting clean text — strip the data:...;base64, prefix first.
- Confusing Base64 with encryption — it only encodes data, it does not secure it.
Frequently asked questions
Does this upload my text anywhere?
No — encoding and decoding run entirely in your browser, so nothing you paste is sent to a server.
Is Base64 a form of encryption?
No. It re-encodes data into text so it survives transport; anyone can decode it, so never use it to protect secrets.
Is Base64 secure?
No — it's encoding, not encryption. Anyone can decode it.
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Cite this tool
Zerdly. (2026). Base64 Encoder / Decoder. Retrieved from https://www.zerdly.com/tools/base64-encoder-decoder/
Tip: Enter any known values to calculate the remaining results.
Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.