How to Zip a Folder Online, Step by Step

Last reviewed 2026-04-27. Open the zip tool to compress a folder in your browser without uploading it.

Five steps on desktop

1. Pick the folder. Drag the folder onto the drop zone in the zip tool. The browser uses the File System Access API or a directory-picker fallback and reads every file inside, including nested subfolders.
2. Keep the structure. The tool defaults to preserving the folder layout inside the zip. Recipients unzip and see my-folder/sub/file.txt exactly the way you sent it. Do not flatten unless you specifically need a flat layout - unzip tools handle nested structures natively, and the metadata makes the archive self-documenting.
3. Set the compression. Default (level 6) is right for mixed content. Best (level 9) helps for folders dominated by documents, source code, or logs. Store (level 0) is the right pick for folders of photos, videos, or audio - everything inside is already compressed.
4. Name the output. Use a descriptive filename: project-handover-2026-04.zip beats archive.zip. Avoid spaces and special characters when emailing - some clients still re-encode the filename.
5. Download. The zip is built locally. The original folder is untouched.

The mobile workaround

Mobile browsers cannot give a website direct access to a folder - they expose individual files only. Three working paths:

• iOS Files app. Long-press the folder, choose Compress. The output is a zip in the same location. Open it in any app or share it.
• Android. Most file manager apps (Files by Google, Solid Explorer, MiXplorer) include a Compress action with the same shape - long-press, Compress.
• Browser-side multi-select. Select all files inside the folder (one at a time on iOS Safari, multi-select on most Android browsers) and drop them into the zip tool. You lose the nested structure unless you re-create it manually.

Size traps to avoid

A folder with one giant file inside (a video, a database dump) zips down very little because that file is the bottleneck. Compress or trim it first. A folder with 20,000 tiny files zips down a lot but creates a slow archive - some unzip tools time out on archives with too many entries. If you see that pattern, group the small files into subfolders or pre-bundle them into a tar before zipping.

Verify the zip before sending

Open the downloaded zip locally to confirm the structure and that every expected file is inside. Unzip a file in the browser will list contents without extracting. For background on the format trade-offs, see online zip vs 7z vs rar or the zip tools hub.