How to use Create ZIP
- 1
Open the Create ZIP tool
Go to tools.slaytic.com and open the Create ZIP tool. No sign-up or account required.
- 2
Add your files
Drop in as many files as you need, of any type. Nothing is uploaded.
- 3
Download the archive
Save the single ZIP file, ready to send or store.
How this works in your browser
The archive is built by a JavaScript ZIP library working entirely in your browser: each file is read into memory, run through the DEFLATE compression algorithm, and written into the archive structure along with the directory entries that let any unzipping tool find the contents. DEFLATE works by finding repeated sequences and replacing them with back-references, which is why it is transformative on text and code and nearly pointless on media files whose redundancy has already been eliminated by their own compression. Because the whole archive is assembled in memory rather than streamed to a server, the limit is your device’s available memory, and the corresponding benefit is that confidential documents are bundled without ever being uploaded.
Create ZIP vs. traditional online converters
| Feature | Create ZIP (in-browser) | Traditional online converters |
|---|---|---|
| File upload required | No - never leaves your device | Yes - file is sent to a server |
| Processing queue | None - starts instantly | Often, especially at peak times |
| Watermark on output | Never | Common on free plans |
| Usage limits | None - free, unlimited use | Often capped per day or file size |
| Works offline once loaded | Yes, for most tools | No - requires a live connection |
| Account required | No | Often, for anything beyond a trial |
Who uses Create ZIP
Sending many files at once
Bundle a batch of documents or images into one attachment instead of several.
Getting past attachment rules
Work around email systems that block certain file types or limit attachment counts.
Archiving a project folder
Package related files together so they stay grouped and organised.
Bundling confidential documents
Combine sensitive files for transfer without uploading them to a compression service.
Frequently asked questions
Is there a limit on how many files I can zip?
No hard limit, though very large batches take longer to compress since everything runs in your browser.
Can I zip files of any type?
Yes, any file type can be added to the archive.
Are my files uploaded to a server to create the ZIP?
No. The archive is built entirely in your browser using JSZip; your files never leave your device.
Can I password-protect the archive?
No. ZIP encryption is not something this tool offers, and it is worth knowing that the traditional ZIP password scheme is weak and crackable in any case. For genuinely confidential material, use encryption software such as 7-Zip with AES, or an encrypted transfer service.
Why did my files barely get smaller?
Because they were already compressed. JPEGs, PNGs, MP4s, MP3s and PDFs have had their redundancy squeezed out already, so a ZIP has almost nothing left to find. The real benefit with those is bundling many files into one, not shrinking them. Text, CSV, code and uncompressed formats compress dramatically by comparison.
What is the practical size limit?
Your device rather than a policy. Because the archive is assembled in memory in your browser tab, very large batches can exhaust available memory, particularly on a phone. Several hundred megabytes is usually comfortable on a desktop; splitting into smaller archives is the answer beyond that.
Will the recipient be able to open it?
Yes. ZIP is handled natively by Windows, macOS, Linux, iOS and Android with no extra software, which is exactly why it remains the default for sending a batch of files.