Help center
Questions, answered.
The practical details behind local ZIP building.
Do my files leave my device?+
No. File processing takes place in your browser. Your source files are not uploaded to merge.zip.
Why is the new builder faster?+
Files selected from an existing ZIP keep their compressed bytes. merge.zip copies them into the new archive instead of decompressing and compressing them again. Other files use the fast, uncompressed ZIP storage mode.
Which archives can I browse?+
Standard ZIP archives are supported. ZIP64, encrypted ZIPs, TAR, GZIP, RAR, and 7z are not currently supported for browsing. You can still include any of those files as ordinary files inside a new ZIP.
Does merge.zip compress new files?+
No. New files are stored without additional compression for maximum speed. Entries copied from an existing ZIP preserve the compression they already have.
How are duplicate filenames handled?+
You can automatically rename duplicates, keep the first file, or keep the last file. The build summary tells you how many conflicts are present before you save.
Why does the browser ask where to save?+
Supported browsers can write the archive directly to a location you choose. Other browsers use their normal download behavior instead.
Which browsers work best?+
Current versions of Chrome, Edge, Firefox, and Safari are supported. Direct save-to-disk availability depends on the browser; the download fallback works everywhere else.