ZIP File Maker

ZIP File Maker — runs in your browser

Everything below happens on this page. No file is uploaded, there is no account, and nothing is watermarked.

Packing files locally is more useful than it sounds. A folder of 200 exported images becomes one archive that a client can actually download. A set of generated clips becomes a single deliverable instead of a thread of attachments. A ZIP you received unpacks without you needing a desktop utility or an online converter.

The compression runs on your own machine using fflate, a MIT-licensed library that does the DEFLATE work in a few kilobycles of JavaScript. Nothing is sent to a server, so there is no account, no per-file fee, and no 100 MB ceiling imposed by someone else.

What it does

Everything is done on your device, so there is nothing to upload and nothing to wait for a queue.

How to use it

Four steps, and none of them leaves your machine.

1. Add files

   Drop them in, or drop a folder to add everything inside it.

2. Choose a compression level

   Level 0 for images and video, level 6 for text, documents and anything compressible.

3. Build the archive

   Compression runs in the browser. Large text-heavy sets take longer than media.

4. Download

   One .zip file containing everything you added.

What people use it for

The jobs this actually gets used for.

Why local zipping is worth the small wait

The obvious method is to upload the files somewhere, and that has costs you only see after the fact.

Zipping on a server means your files make a round trip to a machine you do not control, get written to someone else's disk, get processed, and come back. That is a real wait multiplied by your upload bandwidth, and it puts copies of your files in a place you have no handle on afterwards.

Locally, the cost is CPU time instead of network time. For images and video that is the better trade, because those formats are already compressed — re-deflating a JPEG usually achieves nothing while the upload still costs you the full file size in time. Text, CSV and JSON are where local compression really pays, often cutting them to a quarter of the original.

One thing to know is that compression level is not universally better. On already-compressed media, level 0 is not worse — it is simply faster and produces essentially the same file. Spending minutes deflating a folder of MP4s to save two percent is the wrong end of the trade.

What it cannot do

The honest list, so you do not find out halfway through a batch.

• The archive is held in memory while it is built. Very large sets can exhaust the tab, especially above a few gigabytes.
• No encryption or password protection. Anyone with the file can read it, so do not treat a ZIP as secure.
• Very old ZIP features are not supported — spanning archives and some exotic compression methods will not open.
• Filenames are preserved as given. Characters outside the basic set may appear mangled in older Windows extractors.

Built on open source

The processing is done by a published, licensed library — you can read exactly what runs on your device.

This page uses fflate (3k+), released under MIT. It runs entirely in the browser tab, which is why your files never leave the machine: there is no server to send them to. Nothing here calls an API, and there is no account to create.

Related guides

Longer reads on the same workflow, from the OpenFilmo blog.

Other free browser tools

Same principle: they run on your device and cost nothing to use.

Frequently asked questions