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Base64 Decode & Encode

Encode text or a file. Decode Base64 back to its original bytes. Your input stays in this browser and is never added to the tool link. Base64 is an encoding, not encryption.

Auto guesses the direction. Choose Encode or Decode for an exact choice; use Decode for binary Base64.

URL-safe outputKeep = paddingInclude data URL headerFormat decoded JSON

↑ Encode a file↗ Open Base64 text file

Maximum source file, UTF-8 text or decoded output: 5 MiB. Base64 text input: 8 MiB. Files are read locally.

InputText or Base64

Ready for input

OutputWaiting for input

Nothing to copy or download yet

JWT inspection

Read-only inspection. The signature and authenticity are not verified. Do not use these claims to make authentication or authorization decisions.

Header

Payload

Signature (Base64URL)

Standard & URL-safe

Decode standard (+ /) or URL-safe (- _) Base64. ASCII whitespace is ignored and missing trailing padding is restored. Invalid characters, mixed alphabets and incorrect padding are reported.

Files stay intact

Encode any file type. Decoded downloads preserve every original byte. PNG, JPEG, GIF and WebP images can be previewed up to 24 megapixels; other binary files show a hexadecimal preview.

Clear limits, useful results

Large text previews show the first 65,536 characters; Copy and Download use the full result. JWT inspection supports three-part tokens up to 64 KiB and never verifies signatures.