What compresses well — and what does not
Text files, documents, spreadsheets and code shrink dramatically (often 70–90%). Photos, videos and already-compressed files (JPG, MP4, existing ZIPs) barely shrink at all — that is normal, not a failure: you cannot squeeze water from a stone twice. The tool reports original vs ZIP size honestly, including when the ZIP ends up slightly larger (small files carry ZIP overhead).
How it works
Compression uses the DEFLATE algorithm via the JSZip library, running locally. No account, no upload, no file-size games: if a file is too large for your device's memory, the tool says so instead of silently failing.
Frequently Asked Questions
Why did my ZIP barely shrink?
Photos, videos, music and existing archives are already compressed — ZIP cannot compress them further. Text and documents shrink the most.
Is there a file size limit?
Only your device's memory. Very large files (gigabytes) may fail in a browser tab — that is a browser limit, not a paywall.
Can I password-protect the ZIP?
Not with this tool — browser ZIP libraries do not offer strong encryption. For sensitive files, encrypt them before zipping with a dedicated tool.
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