Base64 Decoder – Decode Base64 Encoded Data Online
Decode Base64 back to text in your browser. Nothing is uploaded.
1 · Input
2 · Output
Padding is optional, whitespace is ignored, and the URL-safe alphabet is accepted. Input that is not valid Base64 is reported rather than decoded into nonsense.
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About our Base64 Decoder
Our Base64 Decode and Encode, a simple and easy online tool that does exactly what it says:
Decodes from Base64 encoding. Encodes into it swiftly and easily. Base64 encodes your data without trouble or decodes it into user-friendly readable format.
Base64 encoding systems are commonly used when there is a requirement to encode binary data, particularly when that data needs to be collected and exported over media that are designed to deal with text. This Base64 encoding helps to assure that the data remains intact without adjustment during transport. Base64 is normally used in various applications as well as collecting complex data in XML or JSON.
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Quick answer
Paste a Base64 string into the input box and the tool instantly converts it back to readable text.
Key facts
- Runs entirely in your browser via JavaScript's built-in Base64 functions
- Decodes standard Base64-encoded text (A-Z, a-z, 0-9, +, /)
- No file upload or server round-trip involved
- Free with no usage limit
- Invalid Base64 input will fail to decode correctly
What is this tool?
This decoder reverses Base64 encoding: it takes a string made of the 64 Base64 characters and reconstructs the original text it represents. It is the counterpart to our Base64 encoder.
How to use it
Paste your Base64-encoded text; the decoded original text appears instantly, ready to copy.- Paste the Base64-encoded text you want to decode.
- The tool instantly displays the decoded original text.
- Copy the decoded result.
Example
Example: decoding "SGVsbG8=" produces the original text "Hello".How it works
The page uses the browser's built-in Base64 decoding functions (such as `atob`) to convert your encoded text back into its original bytes/text, entirely in your browser.Common use cases
- Reading Base64 values found in APIs, JWT payload segments, logs or configuration files
- Checking what an encoded email attachment header contains
- Verifying your own encoded output round-trips correctly
Benefits
Free, instant, and requires no software installation.Limitations
The input must be valid Base64 — stray characters or missing padding produce an error or garbled output. Decoding binary data (like images) as text will show unreadable characters; the tool is designed for text payloads.
Privacy & your data
Decoding runs entirely in your browser. The data you paste never leaves your device.
Frequently asked questions
What if my Base64 input is invalid?
Can this decode Base32 text too?
Is my text sent to a server?
Is this tool free to use?
Last reviewed: