100% Private
Files are zipped locally in your browser and never uploaded to any server.
ZIP File Compressor
Compress files to a ZIP archive online — free, instant, and entirely in your browser. No upload, no signup, no size limit.
Drop files here or browse
Select multiple files to compress into one ZIP archive
100% client-side — your files never leave this device.
Why compress files with TechTools?
Many files, one ZIP
Bundle any number of files of any type into a single downloadable archive.
Adjustable level
Choose Fastest, Balanced or Smallest to trade speed against archive size.
Free & instant
No signup, no install, no size limits — download your ZIP right away.
How to compress files into a ZIP
-
Add your files
Drag and drop them onto the upload area above, or click it to browse. Any file type works, and you can add as many as you like.
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Choose a compression level
Pick Fastest (level 1), Balanced (level 6) or Smallest (level 9). Balanced is right for almost everything.
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Create the ZIP
Name the archive and hit Create ZIP archive. It is built on your own device — nothing is uploaded to a server.
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Download and share
Download the finished
.zipand send it as one attachment or link instead of dozens of separate files.
Does zipping actually make files smaller?
Sometimes a lot, sometimes not at all — it depends entirely on whether the file is already compressed. ZIP works by finding repeated patterns, and formats like JPEG or MP4 have already removed those. Here is roughly what to expect, and what to use instead when ZIP cannot help.
| File type | Typical ZIP saving | Better option to shrink it |
|---|---|---|
| Text, CSV, JSON, XML, logs | 60–90% | ZIP is ideal — nothing beats it here |
| Source code, EXE, DLL | 40–70% | ZIP is ideal |
| BMP, TIFF, RAW photos | 30–70% | Convert to JPEG or WebP with the Image Editor |
| 5–20% | Rebuild it with the PDF Editor | |
| Word, Excel, PowerPoint | 2–10% | Already ZIP files internally — little left to gain |
| JPEG, PNG, GIF, WebP | 0–3% | Re-compress or resize in the Image Editor |
| MP3, MP4, MOV, H.264 | 0–2% | Re-encode at a lower bitrate in the Video Editor |
Even when ZIP cannot shrink a file, it is still worth using: bundling twenty attachments into one archive is what makes them sendable by email in the first place, and it preserves folder names, ordering and file dates.
Zipping files on Windows, Mac, iPhone and Android
Windows
Select the files, right-click and choose Send to → Compressed (zipped) folder. Windows offers no compression-level choice, and it cannot zip files from different drives in one go.
macOS
Select the files, right-click and choose Compress. macOS adds a hidden
__MACOSX folder that shows up as clutter for Windows recipients —
this tool does not.
iPhone & iPad
In the Files app, tap Select, choose the files, then More → Compress. It only works on files already saved into Files, so anything in another app has to be exported first.
Android
There is no built-in zipper on most Android builds — you normally need a file manager app. Opening this page in Chrome does the same job with nothing to install.
Use this tool when you are on a device you do not control, on a phone, on a Chromebook, or when you want to pick the compression level yourself — the ZIP it produces is a standard archive that opens natively everywhere.
Frequently asked questions
How do I compress files into a ZIP online?
Drop your files onto the upload area (or click to browse), pick a compression level, and click Create ZIP archive. Your ZIP is built instantly in the browser and ready to download.
Are my files uploaded to a server?
No. Compression runs 100% in your browser using JSZip — your files never leave your device, so it's completely private.
Is the ZIP compressor free?
Yes, it's completely free with no registration, no watermarks and no file-count limits.
Which compression level should I choose?
Fastest (level 1) is quickest, Smallest (level 9) squeezes the archive the most, and Balanced (level 6) is the recommended middle ground for everyday use.
Is there a file size limit?
There's no server-side limit because nothing is uploaded. The practical ceiling is your device's available memory, since the whole archive is built in the browser.
Can I compress many files at once?
Yes — select or drop as many files as you like and they're combined into one single .zip archive you can share in one link or email.
Does zipping actually make files smaller?
It depends on the file type. Text, CSV, JSON, XML, log files, source code and uncompressed images like BMP or TIFF shrink dramatically — often by 60–90%. Formats that are already compressed internally — JPEG, PNG, GIF, MP3, MP4, and Office files like .docx or .xlsx — barely shrink at all, usually under 3%. ZIP always still helps by bundling many files into one, even when it can't shrink them.
How do I compress a folder?
Open the folder, select everything inside it (Ctrl+A on Windows, Cmd+A on Mac) and drop those files onto the upload area. The ZIP will contain all the files as a flat list rather than a nested folder.
How do I open or unzip a ZIP file?
Every modern operating system opens ZIP files without extra software. On Windows, right-click the .zip and choose Extract All. On macOS, double-click it. On iPhone and Android, tap the file in the Files app and it expands in place.
Can I password-protect the ZIP archive?
Not yet — this tool creates standard unencrypted ZIP archives. For confidential files, the archive itself is still built entirely on your device and is never uploaded, so nothing is exposed in transit to us.
Is it safe to compress files online?
With this tool, yes — because nothing is actually sent online. The compression runs in your browser's own memory, so no file data reaches our servers, there's nothing to intercept, and there's no copy left on a server to delete afterwards. That's not true of most online compressors, which upload your files first.
Which is better, ZIP, RAR or 7z?
ZIP is the safest choice for sharing because every operating system opens it natively with no extra software. 7z usually produces smaller archives and RAR sits in between, but both need a separate app such as 7-Zip or WinRAR to open, so the recipient may get stuck.