Frequently asked questions (FAQ)

General Questions

Can I use OnlineZipTools for free?

Yes, it's completely free.

Will the file be uploaded to the server?

No, files are processed only within the browser and not sent to the server at all.

Which browser can I use it?

Works with the latest versions of Chrome, Firefox, Safari and Edge.

Can I use it on a mobile device?

Yes, it can also be used on smartphones and tablet browsers.

Are there any limits on the file size that can be processed?

There are no technical limitations, but due to browser memory limitations, very large files may not be able to be processed.

Do I need an internet connection?

Once the page is loaded, it can also be used offline.

Compression questions

What format can I compress it?

Currently, it supports compression in ZIP and 7z formats.

Can I compress multiple files at once?

Yes, you can drag and drop multiple files and folders to compress them into one archive file.

What is the difference between compression levels?

The higher the compression level, the smaller the file size, but the longer the processing time.

How strong is password protection?

It uses AES-256 encryption and provides military-level encryption strength.

Is the folder structure preserved?

Yes, it preserves metadata such as the original directory structure, file names, and timestamps.

What causes the compression failure?

There may be a lack of memory, unsupported file formats, or browser restrictions.

Should I choose ZIP or 7z?

If you are concerned about compatibility, we recommend ZIP, and if you want to reduce the file size, we recommend 7z.

Is it okay to close the browser while compressing?

No, the process will be suspended.

Questions about thawing

What format can I unzip files?

Compatible with major archive formats such as ZIP, 7z, RAR, TAR, GZ, BZ2, XZ, LZMA, and more.

Can I unzip the files with a password?

Yes, you can unzip password-protected ZIP or 7z files by entering the correct password.

How do I download the unzipped file?

Once the decompression is complete, you can either download the files individually or download all files at once.

Can I unzip corrupted archive files as well?

It may be possible to unzip the file if it is minorly damaged, but it cannot unzip the file that is significantly damaged.

Password error occurs when unzipping

The password may be incorrect or an unsupported encryption method.

How long does it take to unzip a large archive file?

Depending on the file size and browser performance, files of several GB can often be unzipped in a few minutes.

Security questions

Doesn't the file really send to the server?

Yes, all operations are performed in the browser using WebAssembly.

What happens to the file data after processing?

After the process is completed, all file data will be automatically deleted from the browser's memory.

Can I safely process confidential files?

Yes, because it is locally processed, it can safely compress and unzip sensitive files.

Is passwords secure?

Passwords are also used only within the browser and are not sent outside.

Will there be a virus scan?

It does not have a virus scan function, but it is safe as it does not change the contents of the file.

Technical questions

What is WebAssembly?

It is a technology that allows you to run native code quickly within a browser, and is used to make the 7-Zip library run in the browser.

Can I use it even if I have JavaScript disabled?

No, you need JavaScript and WebAssembly.

Is the source code published?

The 7-Zip library is open source.

Is there a way to improve the processing speed?

Using a modern browser and closing other tabs may help speed up.

Out of memory error occurs

Close the browser tab to free up memory or split it into smaller files for processing.

The progress bar isn't progressing?

For large files, processing may take some time.

An error message has been displayed

It could be a browser compatibility or file format issue.

troubleshooting

Page not loading properly

Clear your browser cache or try using private browsing mode.

Can't drag and drop files

This could be caused by browser settings or security software.

Processing will stop halfway through

This is due to insufficient memory or browser limitations.

Download button not displayed

The process may not be completed or the browser's pop-up blocking function may be caused.

Japanese filenames are garbled

Older ZIP files may cause character encoding issues.

Other inquiries

If you have any issues that are not resolved above, please contact us with details such as browser type and version, error message, file size, etc.