DEFLATE Compress
Compress text or encoded binary data using Zlib or Raw DEFLATE and output the result as Hex or Base64. Read more
What is Deflate compress?
DEFLATE is the lossless compressed-data format specified in RFC 1951. A raw DEFLATE stream contains compressed blocks only; the Zlib format adds a small header and an Adler-32 check value. This tool creates either representation from text or encoded bytes. ZIP and Gzip use DEFLATE in different containers and are not interchangeable with these outputs.
How to use this tool
Enter text or encoded bytes, choose the byte encoding, select Zlib or Raw DEFLATE, set compression level 0–9, and output the result as Hex or Base64. The receiving implementation must expect the same wrapper. Use DEFLATE Decompress for the reverse operation.
Choosing the right format
Choose Zlib for systems expecting RFC 1950 framing and Raw DEFLATE only when the surrounding protocol supplies its own framing. Level 0 stores data without compression; higher levels trade processing time for a potentially smaller stream. Base64 is more compact than Hex for transporting binary data as text.
Important limitations
Compression provides no confidentiality. Zlib’s Adler-32 detects accidental corruption but is not cryptographic authentication; raw DEFLATE has no wrapper checksum. Short or already-compressed input may grow, and browser memory limits make streaming software preferable for large data.
Frequently asked questions
Why can another program not open the result?
The most common cause is a wrapper mismatch: Zlib data passed to a raw inflater, or raw DEFLATE passed to a Zlib decoder. Also decode the Hex or Base64 representation back into bytes before inflating it.
Are my files uploaded?
No. The input is compressed locally in your browser. To create an actual archive, use ZIP Create or Gzip Create.