Create a ZIP file

What a ZIP file is

A ZIP is a single container holding any number of files and folders, each individually compressed. It has been the standard way to bundle files since the early 1990s and is opened natively by Windows, macOS, iOS, Android and every Linux desktop without extra software. That universality is the main reason to use it: one attachment instead of twenty, one download link instead of a folder full of them, and the recipient does not need to install anything.

What compression actually saves

ZIP uses DEFLATE compression, which is very good at squeezing text, spreadsheets, source code, uncompressed images and databases, and does almost nothing for files that are already compressed. In practice:

So a ZIP of photos is barely smaller than the photos, but it is still one file, which is often the point. If the goal is a smaller photo set, compress the images first and then zip them.

Compression levels

Store does no compression and is instant; use it for photos, video and anything already compressed. Normal is the sensible default. Maximum spends more time for a small extra gain, worthwhile for large text-heavy archives and pointless for media.

Practical uses

• Sending a project folder of documents to a client as one attachment.
• Bundling exported reports, invoices or statements for an accountant.
• Packaging a website's files or a font family for delivery.
• Collecting a set of photos into a single download for a shared album.
• Keeping a dated snapshot of a folder for backup.

Limits to know about

The archive is built in your browser's memory, so a few hundred megabytes is fine on a laptop, while several gigabytes may not be on a phone. Folder structure is kept if you drop a folder. File names with characters outside the basic Latin set are stored in UTF-8, which every modern unzipper reads correctly. Nothing is uploaded at any stage, so the files inside stay private.