Decode standard or URL-safe Base64 strings back to plain text and UTF-8 data.
Base64 Decoding reverses Base64 encoded ASCII strings back to their original binary or UTF-8 text representations.
A Base64 decoder converts Base64-encoded strings back into their original plain text or binary format. OneToolBox's Base64 Decoder processes data entirely in your browser using native JavaScript atob() — your encoded tokens, API keys, and binary data never leave your device. The tool auto-detects standard and URL-safe Base64 variants and validates input before decoding.
Yes. The decoder automatically detects and handles both standard Base64 (with + and /) and URL-safe Base64 (with - and _) variants.
The tool validates the input before decoding and displays a clear error message if the string contains invalid characters or has incorrect padding.
Yes. If the Base64 string represents an image (e.g., a data URI), the decoder will output the binary image data which you can save as a file.
No. All decoding happens locally in your browser using native JavaScript functions. Your data never leaves your device.
