How to decode Base64
- Paste your Base64 string into the Input box. Data URIs and URL-safe Base64 are accepted too.
- The decoded text appears instantly in the Output box. If you see strange characters, pick another character set.
- Click Copy or Download. Binary results such as images or PDFs are saved as a file with the right extension.
A Base64 decoder and encoder in one
Base64 Decoder Online converts in both directions. The decoder ignores spaces and line breaks, accepts the URL-safe alphabet (- and _) and adds missing = padding automatically, so even messy strings copied from logs, emails or APIs decode correctly. The encoder supports UTF-8, UTF-16 and Latin-1 text, URL-safe output and MIME line breaks.
How Base64 decoding works
Every 4 Base64 characters represent 3 bytes of data. The decoder maps each character back to its 6-bit value, joins the bits and splits them into bytes, which are then interpreted as text using the selected character set. For example, SGVsbG8= decodes to Hello.
Decode Base64 on the command line
On Linux and macOS use echo 'SGVsbG8=' | base64 --decode. In Windows PowerShell use [Text.Encoding]::UTF8.GetString([Convert]::FromBase64String('SGVsbG8=')). In Python: base64.b64decode('SGVsbG8=').decode().
Why use Base64 Decoder Online?
- FreeEvery tool is free with no limits, accounts or watermarks.
- PrivateProcessing happens locally in your browser. Files are never uploaded.
- FastLightweight pages that load instantly on any device.
- Works everywhereUse it on Windows, macOS, Linux, Android and iPhone.
Frequently asked questions
Is Base64 a form of encryption?
No. Base64 is an encoding, not encryption. Anyone can decode it without a key, so never use Base64 alone to protect passwords or private data.
Why does my decoded text look garbled?
Either the text was encoded with a different character set (try UTF-16 or Windows-1252) or the Base64 contains binary data such as an image, a PDF or a ZIP file. Use Download to save binary data as a file.
What is URL-safe Base64?
Base64URL replaces + with - and / with _ and usually drops the = padding, so the result can be used in URLs, file names and JSON Web Tokens. This decoder reads both variants automatically.
Is my data sent to a server?
No. Decoding and encoding happen locally in your browser with JavaScript. Nothing you paste is uploaded or stored.