How to decode Base64
- Paste the Base64 string into the left box — decoding happens live.
- URL-safe Base64 and missing
=padding are fixed automatically. - Copy the result, or hit ⇄ Swap to re-encode it.
What you'll find inside Base64 strings
Base64 shows up everywhere in a developer's day: Authorization: Basic headers hide a user:password pair, JWT tokens carry two Base64-encoded JSON documents, email sources encode attachments, and config files smuggle binary values through text-only formats. When something looks like a random wall of letters ending in =, it's usually Base64 — paste it here to see what it says.
Frequently asked questions
How do I decode a Base64 string?
Paste the Base64 into the input box — the decoded text appears instantly. URL-safe Base64 (- and _) and strings with missing = padding are handled automatically.
Why does my Base64 string fail to decode?
The most common causes are stray whitespace inside the string, characters outside the Base64 alphabet, or pasting only a fragment. This decoder trims whitespace and fixes padding automatically, which solves most cases.
Can I decode a JWT token with this?
Yes — paste the header or payload segment of the JWT (the parts between the dots) and you'll get the JSON. The signature segment is binary and won't decode to readable text.
Is the decoded data private?
Yes. Decoding happens entirely in your browser — tokens, credentials and payloads never leave your machine.