zlib / gzip compress & decompress
Quickly compress or inflate gzip/zlib data.
Choose compression or decompression, then inspect the result as text, Hex, or a file.
Local · no upload · encoding is not encryptionProcessing rules, data integrity & privacy
- Choose zlib, gzip, or raw DEFLATE explicitly; the format is not guessed. ZIP, preset dictionaries, multi-member gzip, and compression-level controls are not supported. Base64 on both sides does not mean compression was skipped.
- Encoded input must pass strict Base64 / Hex validation. Samples follow the current mode; when decompression starts from text, the sample switches explicitly to Base64 and explains the change.
- UTF-8 decoding is strict and preserves BOM. Non-text results can be viewed as Hex or downloaded. Text areas may normalize line breaks, so use files for exact round trips.
- Input limit: 1 MiB; result limit: 4 MiB; encoded text is additionally limited to 4 Mi UTF-16 units. Decompression checks size incrementally and returns no partial result on overflow. Peak browser memory cannot be fully bounded. Tasks time out after 10 seconds and can be cancelled.
- Preview shows up to 65,536 UTF-16 units; copy and download still use the complete result. Switching views does not rerun the operation; editing source data or operation settings disables stale results.
- Clearing or replacing with a sample requires confirmation and cannot be undone. Data is processed only in this page’s memory and Worker; it is not uploaded, written to URLs or persistent storage, or executed as HTML. Results are released when you leave, so keep your own backup.
Frequently asked questions
How do I use it?
Paste or choose a file, then compress or decompress.
Is anything uploaded?
Everything runs locally in your browser and is not uploaded.
How is this different?
PDF/image compressors are document-oriented; this is raw byte compression.