Base64 to Text — Free, in Your Browser
The mirror job: you have a Base64 blob — in an email header, a data URI, a config file, an error message — and you need to see what is inside before you do anything with it.
Base64 Encoder / Decoder
Encode & decode — 100% local
Why convert Base64 to Text
The mirror job: you have a Base64 blob — in an email header, a data URI, a config file, an error message — and you need to see what is inside before you do anything with it. Decoding it in your browser means the decoded content (which is sometimes the secret itself) never round-trips through a web service.
Paste the blob, see the result instantly. If the result is binary (an encoded PNG or PDF, for example), you will see text that looks random — that is the correct output for binary data; the encoder/decoder here is for text payloads, and file payloads are best handled by the dedicated tools.
How to do it (3 steps)
- Paste the Base64 string.
- The decoded text appears instantly.
- Copy it or investigate further.
Technical note
The decoder tolerates the usual real-world noise: surrounding whitespace and newlines (wrapped at 76 characters, as MIME requires) are stripped before decoding. If the input length is not a multiple of 4 after cleanup, the decoder reports it rather than guessing — a truncated Base64 string is almost always a copy-paste cut, and decoding the wrong tail silently is how people end up debugging the wrong secret.
The mistake worth avoiding
The common mistake is debugging the decoded content when the real problem is a truncated input. A Base64 string copied from a wrapped email, a cut log line, or a chat message that clipped the paste loses its tail — and the decoder's invalid-length error is that cut announcing itself. Before you question the encoding, count: strip whitespace, check the length is a multiple of four, and only then investigate the source. One more trap in the same family: pasting anything that is not payload, a subject line, a colon, a data: prefix from an HTML attribute. The decoder treats every extra character as data, and a single stray line wrap in the middle of the string can silently corrupt the tail of the decoded result.
FAQ
- Is the string uploaded for decoding? No — decoding is local. Paste a secret, read it, and it has touched nothing but your machine.
- Why does it say invalid length? Base64 must be a multiple of 4 characters (ignoring whitespace). Your blob was probably cut off in copy-paste.
- Can it decode file data URIs? It decodes the Base64 portion to text; for recovering an actual image or PDF from a data URI, use the image tools instead.
- Why does decoding give me binary gibberish? Because the original was not text — it was an image, a PDF, or another binary blob, correctly encoded and correctly decoded. Base64 does not know what it is carrying. To recover a file, use a file-aware tool; to read a string, this is the right place.
Base64 Encoder/Decoder — full tool →