Base64 Decoder

Decode Base64 strings back to plain text instantly in your browser. Convert encoded data from APIs, emails, and data URIs back to readable content

TEXT CODE
Encode Decode
Tip: paste a Base64 string on the left — output updates instantly.

Runs 100% Locally in Your Browser

This tool processes your data entirely on your device. Nothing is uploaded, stored, or sent to any server.

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Frequently Asked Questions

How to decode a Base64 string back to plain text?
Paste the Base64-encoded string into the input and the tool instantly outputs the decoded text.
Why does a Base64 encoded string end with = or ==?
Base64 encodes data in 3-byte blocks; = padding is added when the input length isn't a multiple of three.
What happens if I try to decode an invalid Base64 string?
The tool will report a decode error — common causes are missing padding characters or characters outside the Base64 alphabet.
What is the difference between Base64 decoding and decryption?
Decoding reverses an encoding scheme and requires no key; decryption reverses encryption and requires a secret key.
What format should the Base64 input be in?
Standard Base64 uses A–Z, a–z, 0–9, +, /, and = padding; URL-safe variants use - and _ instead of + and /.
Are my inputs stored or logged anywhere when decoding Base64?
No. Decoding runs entirely in your browser — nothing is stored, logged, or transmitted.