Base64 Decoder
Paste a Base64 string to decode it to text — or switch to File to download the original binary.
Nothing leaves your browser
Safe for JWTs, API keys, and private payloads.
Decodes as you type
No submit button — output updates on every keystroke.
Text or binary
Read decoded text or download images, PDFs, and archives.
How the Base64 decoder works
Base64 packs three bytes of binary data into four printable characters. The decoder reverses that mapping: each group of four characters becomes three bytes, padding = characters are discarded, and the resulting bytes are rendered as UTF-8 text or offered as a file download.
Need the reverse? Use Base64 Encode. For binary payloads, try Base64 to Image or Base64 to PDF.
Frequently asked questions
›What is a Base64 decoder?
A Base64 decoder converts a Base64-encoded ASCII string back into the original bytes — text, an image, a PDF, a certificate, or any other binary payload.
›Is this Base64 decoder free?
Yes, completely free with no sign-up, no ads on the tool, and no limits on how many strings you decode.
›Does the decoder support URL-safe Base64?
Yes. Strings using - and _ instead of + and / are normalized automatically, and missing = padding is restored before decoding.
›Can I decode Base64 into a file?
Yes. Switch to the File tab, paste the Base64 blob, and download the decoded binary. Data URL prefixes like data:image/png;base64, are handled for you.
›Is it safe to decode secrets and tokens here?
Yes. Decoding uses your browser's native atob and TextDecoder APIs and runs entirely on your device — nothing is uploaded, logged, or stored.
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