Guide1 min readUpdated July 1, 2026
How to decode Base64
Short answer
Paste the Base64 string into a decoder and it returns the original text. For binary data (images, files), decode to bytes rather than text so the result is not corrupted.
What Base64 decoding does
Base64 encodes binary data as 64 safe ASCII characters so it can travel through text-only channels. Decoding reverses that, turning the encoded string back into the original bytes. See what is Base64 for how the encoding works.
Decode a Base64 string
- Paste the stringDrop the Base64 text into the decoder.
- Read the outputText decodes straight to readable characters.
- Watch for URL-safe variantsIf it uses - and _ instead of + and /, it is base64url — decode it as such.
Try it: Base64 Encoder/DecoderEncode and decode Base64 locally — nothing is uploaded.Open tool
How to recognize Base64Base64 uses A-Z, a-z, 0-9, + and /, often ending in one or two
= padding characters, and its length is a multiple of 4. A JWT, for example, is three base64url sections joined by dots.Common pitfalls
- Decoding binary (an image or PDF) as text corrupts it — decode to bytes/file instead
- base64url uses
-and_; decoding it as standard Base64 fails - Missing
=padding can break strict decoders; some are lenient - Whitespace or line breaks inside the string may need stripping first