TEXT & DEVELOPER TOOLS
Base64 Decode
Decode Base64 text back into readable text or a downloadable file, entirely in your browser.
Quick answer: Paste the Base64 string, run the operation, and read the result. For file data, download the decoded bytes; images are previewed.
Use Base64 Decode ↓Loading the tool…
How to use Base64 Decode
- Paste the Base64The operation is already set to Base64 decode. Paste the string, with or without line breaks.
- Pick the right variantUse Base64url decode if the string uses - and _ instead of + and /, as in JWTs and URLs.
- Run and reviewThe decoded text appears in the result box. If it was binary data such as an image, you can preview and download it.
- Copy or downloadCopy the result or save it as a file.
About this tool
Base64 shows up everywhere: email attachments, data URLs, API responses, configuration files and tokens. It is not encryption; it is simply a way of writing binary data using 64 printable characters. This page decodes it locally, so you can inspect what is inside without sending potentially private data to a website that processes it on a server.
Practical example: Paste the Base64 part of a data URL (without the data:image/png;base64, prefix) and see the image preview.
Important limitation: Decoding does not check that the content is safe or meaningful, and binary results cannot be shown as text.
Decoding runs in this browser tab. Your data is not sent anywhere. Read the privacy information.
How it works
The tool converts each group of four Base64 characters back into three bytes, then shows the bytes as UTF-8 text or offers them as a file.
Real-world uses
- Inspecting API responses and configuration values
- Recovering an image from a data URL
- Reading the parts of a token
Decoding Base64 reliably
Base64 turns every three bytes into four characters, which is why encoded data is about a third larger. It ends with one or two equals signs when the length needs padding. Strings that use plus and slash are standard Base64. Strings with minus and underscore, and often no padding, are Base64url, which is used in web tokens and URLs. If a standard decode fails on such a string, switch to the Base64url operation.
The decoded bytes may not be text. If you decode a PNG or a PDF that was embedded as Base64, the result is binary, and displaying it as text produces garbage. In that case download the decoded bytes as a file, or, for images, use the preview. If the decoded text looks like broken characters, the data is probably not UTF-8 text.
Remember that Base64 hides nothing. Anyone can decode a Base64 string, so it provides no protection for passwords or keys. If you find credentials stored as Base64 in a configuration file, they are effectively in plain text.
Common errors are stray whitespace, truncated data copied from a terminal, and a data URL prefix such as data:image/png;base64, which is not part of the encoded content. Remove the prefix and any quotes, then decode the remaining characters.
Tips for better results
- Strip data URL prefixes before decoding.
- Try Base64url if standard decoding fails.
- Treat decoded secrets with care.
Frequently asked questions
Is Base64 encryption?
No. It is a reversible encoding. Anyone can decode it, so it offers no secrecy.
Why does decoding fail?
The string may contain characters outside the Base64 alphabet, be truncated, or use the URL-safe variant. Try Base64url decode, and remove prefixes or quotes.
Can I decode an image or PDF?
Yes. Decode it and download the bytes as a file; images can also be previewed.
Is my data uploaded?
No. Decoding happens in this browser tab.