How to use the Base64 Decode
- Paste the Base64 text in the input — it is decoded as you type.
- URL-safe Base64 (with - and _) and missing = padding are handled automatically.
- Copy the decoded text, or switch to Encode to go the other way.
What Base64 decoding does
Base64 represents binary data with 64 printable characters (A–Z, a–z, 0–9, + and /), four characters for every three bytes. Decoding reverses that and turns the bytes back into text using UTF-8, so accents and emoji come out correctly: SGVsbG8sIHdvcmxkIQ== decodes to “Hello, world!”.
URL-safe Base64 and padding
JWTs, URLs and many APIs use Base64URL, which replaces + and / with - and _ and usually drops the trailing = padding. The decoder accepts both variants and adds the padding back when it is missing.
When the result looks like gibberish
If the decoded output is unreadable, the data is probably not text — an image, a PDF, compressed or encrypted data. For images use Image to Base64 (it decodes data URLs back to pictures), and for JWTs use the JWT Decoder, which decodes all three parts.
Tools that pair well with the Base64 Decode
- URL Decode — Paste a URL or query string full of %20 and %3D to make it readable again — with each query parameter decoded and listed separately.
- HTML Decode — Paste text full of &, < and ’ to turn it back into normal characters — every named and numeric HTML entity is supported.
- Morse Code Translator — Type text to get Morse code, or paste dots and dashes to decode them — then listen to it, watch it flash and download the audio.
- Text to Binary Converter — Type text to see it as binary code, or paste binary (or hex, octal, decimal) to translate it back to readable text.
Frequently asked questions
Is Base64 encryption?
No. Base64 is an encoding anyone can reverse — never use it to hide passwords or secrets.
Why does my Base64 end with = or ==?
Padding. Base64 works in groups of three bytes; when the data length isn’t a multiple of three, = or == fills the last group.
How do I decode a JWT?
A JWT is three Base64URL parts separated by dots. Paste one part here, or use the JWT Decoder to decode the header and payload together.
Can I install Base64 Decode as a web app and use it offline?
Yes. Base64 Decode is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.