Compress files into a ZIP in your browser
Drop files or a folder. The before figure is their combined size, the after figure is the ZIP. Already-compressed photos will barely move; text, CSV and source files will.
or browse your device. Everything is processed on this device
How to create a ZIP
Relative paths from a folder drop are kept. Nothing is uploaded. A single existing ZIP belongs on Compress ZIP instead.
macOS and Windows sidecar files are skipped by default. Turn that off when you need every name preserved.
Text, CSV, JSON and source files are compressed. JPEGs, PDFs, MP3s and similar payloads are stored, because wrapping them again rarely pays.
The result panel compares the uncompressed files with the archive. That is the number that matters when you are creating one, not ZIP versus ZIP.
Why a new ZIP is sometimes barely smaller than the folder
A ZIP is a container. Each file is stored as-is or compressed with Deflate. Text, CSV, JSON and source code repeat themselves, so Deflate finds a lot to take out. JPEG, PNG, PDF, MP3 and MP4 already have a compressor of their own, so a second general-purpose pass usually saves nothing and can add a few header bytes.
That is why the before figure on this page is the files you dropped. Comparing a ZIP we just built with a second pass over the same ZIP would read as "already close to optimal" even when the folder packed down well, or as 0% saved when you zipped photographs that cannot shrink.
To rebuild an archive you already have, use Compress ZIP. This page does not extract files, and it does not unzip.
Create ZIP FAQ
Why is the ZIP almost the same size as my files?
Because the files were already compressed. A folder of JPEGs, PDFs or MP3s becomes a ZIP that is roughly the sum of those files plus a little header. The archive is still useful: one download, folder paths intact. It is not a second compressor for photographs.
How do I make the ZIP smaller?
Compress the heavy payloads first when changing them is acceptable: pictures through the JPG or PNG tools, documents through PDF or DOCX. Then drop the smaller files here. Try harder will offer every file to Deflate, but it cannot make an already-compressed JPEG materially smaller.
Can I zip a folder and keep its structure?
Yes. Drop the folder where your browser supplies relative paths. Unsafe parent segments are removed and duplicate names are made unique. Empty junk folders such as __MACOSX are skipped when Remove junk files is on.
Does this unzip or extract files?
No. Files go in and one ZIP comes out. There is no extraction mode. To shrink an existing ZIP rather than pack new files, use Compress ZIP.
Are my files uploaded?
No. Reading, Deflate and ZIP writing all happen in this browser tab. There is no upload step and no account. The practical ceiling is the memory on your device.
Related
Every file joins the ZIP. Nothing is routed to another tool.