Decode Base85 text in the Adobe Ascii85 form back to bytes, or encode text and files as Ascii85, the variant PDF and PostScript streams use.
Runs in your browser — your input is processed on this device and never uploaded.
Encode data as Adobe Ascii85 or decode Ascii85 text back to binary data.
Results appear here.
Ascii85 packs 4 binary bytes into 5 printable ASCII characters, which is less expansion than the 4 characters per 3 bytes that Base64 spends. This tool implements the Adobe variant, the one PDF and PostScript streams use.
Density. Ascii85 costs about 25 percent overhead against Base64's 33 percent, so on a large payload the difference is real.
The trade is compatibility. Base64 is understood nearly everywhere; Ascii85 is not, and its character set includes punctuation that needs escaping in some contexts. It earns its place when you control both ends and the size matters, which is why it took hold in document formats rather than in web APIs.
Base64 is the safe default and the one every language ships. RFC 1924 Base85 uses a different alphabet from this one, and so does Z85. None of the three are interchangeable, so an Ascii85 decoder will not read RFC 1924 Base85 text and vice versa.
basE91 is denser still. Hex is the least dense of the group and the easiest to read.
Most of the confusion around this format comes from the name. "Base85" refers to at least three incompatible alphabets, so when a tool or a spec says Base85, check which one it means before assuming your data will survive the round trip.
Text wrapped in <~ and ~>, or taken from a PDF or PostScript file, is Ascii85 and decodes here. Text a spec calls RFC 1924 Base85 needs RFC 1924 Base85, and Z85 comes from ZeroMQ.
Warning
None of this protects anything. The transformation is public and trivially undone, and it makes data bigger rather than smaller.
Find similar tools by category or tag.