Paste base64 or hexadecimal zlib data and decompress it into readable text.
Compression tool
Enter a value or load the sample to see the result.
Guide
Decompress base64 or hexadecimal zlib and deflate data online using browser-native decompression when available.
Zlib and deflate payloads appear in APIs, caches, logs, and encoded debugging samples. They are similar to gzip in that they compress bytes, but the wrapper format is different. A gzip decoder will often fail when the input is actually zlib data, which is why a separate focused page is useful.
This tool accepts base64 or even-length hexadecimal input and attempts to decompress it using the browser DecompressionStream API. When the decompressed result is text, it is shown directly in the output area. The page is designed for short pasted values rather than large archives.
A common use case is debugging an encoded field from an API response or a stored diagnostic value. You can paste the compressed text, run the decompressor, and quickly see whether the payload contains JSON, plain text, HTML, or another readable format.
If the output is unreadable, the original payload may be binary, encrypted, not actually zlib, or encoded in another wrapper. Try the gzip decompressor when you know the payload starts as gzip, and use this page for zlib or deflate-style data.
Quick reference
eJzzSM3JyVcozy/KSQEAGgsEXQ==
Decompressed text: / Hello world
Gzip, zlib, and raw deflate are related but not interchangeable. A payload can fail simply because it is using a different wrapper.
The page is designed for pasted base64 or hexadecimal strings, not large binary archives or files.
Decompression uses browser-native APIs when available. Older browsers may not expose the required stream support.
Common mistakes
No. They are related compression formats, but their wrappers differ and they should be decoded with the right tool.
Yes. Even-length hexadecimal input is accepted.
The decompressed bytes may not be text, or the input may not be valid zlib data.