Gzip & Deflate Compressor (fflate)
Compress text or files as Gzip, Zlib or raw DEFLATE with levels 1–9. Restore exact bytes, preview valid UTF-8, compare sizes and download complete files.
About this gzip & deflate compressor (fflate)
Compress text or files as Gzip, Zlib or raw DEFLATE with levels 1–9. Restore exact bytes, preview valid UTF-8, compare sizes and download complete files Runs entirely in-memory using Web Crypto primitives to keep sensitive tokens, certificates, and cryptographic keys secure from third-party interception.
Encoding & cryptographic principles
Compress text or any file to Gzip, Zlib or raw DEFLATE; restore compressed files or Base64 to exact bytes. Select the matching format. Valid UTF-8 previews preserve BOM and NUL; other binary results remain downloadable. Downloads append .gz, .zlib or .deflate when compressing and remove the matching suffix when restoring (otherwise append .decoded). Original names and MIME types are not recovered from headers. Compression uses the installed MIT-licensed fflate library in a local worker, levels 1–9 (default 6); decompression uses the browser DecompressionStream with wrapper integrity checks. Corrupt or truncated data is rejected. These are not ZIP archives. No upload or paid service. Offline use requires page resources to have loaded first. Ratio = compressed bytes / original bytes × 100; savings = 100 − ratio. Results update after each run. Small or incompressible inputs may grow (negative savings); ratios for empty originals are undefined. Higher levels do not guarantee smaller output.
Worked verification example
Scenario: Restore a fixed Gzip Base64 payload.
Sample input:
Second field:
Processing: Choose Decompress, Gzip and Base64 input, then run locally. Download the exact bytes or copy the UTF-8 preview.
Illustrative output:
Security parameters & input constraints
Operational constraints and validation boundaries: Each selected file and UTF-8 text input must be smaller than 50,000,000 bytes (50 MB). Base64 input allows up to 68,750,000 characters including whitespace, with decoded compressed bytes also below 50 MB. Restored output is limited to 64 MiB (67,108,864 bytes). A 30-second timeout covers reading and processing; smaller inputs can still exceed the time or output budget. Cancel, edit, switch options or clear to discard pending work. Long previews are paged; Copy and Download use the complete available result.
Cryptographic digests, encoded strings, and signatures generated by Gzip & Deflate Compressor (fflate) should be verified against target authentication systems before production use.
Client-side Web Crypto boundary
Key derivation, hashing, and encoding in Gzip & Deflate Compressor (fflate) execute in local memory using Web Crypto APIs without remote socket transmission.
Cryptographic specifications & RFC standards
Technical specifications and cryptographic RFC standards governing algorithms and key representations:
Gzip & Deflate Compressor (fflate) verification · Audit standards
How to use it
- Select operation, format, level and text or file input.
- Run locally, then check the byte sizes, ratio and preview.
- Download the full file or copy the available text/Base64 preview.
Frequently asked questions
What can I compress or restore?+
Operational requirements for "What can I compress or restore?" are verified in local memory during execution of Gzip & Deflate Compressor (fflate).
What are the limits?+
Each selected file and UTF-8 text input must be smaller than 50,000,000 bytes (50 MB).
How are compression ratios calculated?+
Runtime handling of "How are compression ratios calculated?" executes synchronously in your browser tab without remote delays.
How does local processing work?+
No. All compression and decompression operations execute entirely client-side using JavaScript Web Workers and the native DecompressionStream API. No file data, compressed chunks, or plain text strings are transmitted to remote servers.