Question 1

Are files uploaded to a server?

Accepted Answer

No, Word, Excel, and PowerPoint files are ZIP archives internally — the tool unpacks and repacks them entirely in your browser.

Question 2

Will the content or formatting change?

Accepted Answer

Text, styles, and formatting are always kept as-is. Embedded JPEG images are only affected if you lower the quality slider below 100% — in that case they're re-compressed and lose a little visual quality in exchange for a smaller file.

Question 3

How much smaller will the file get?

Accepted Answer

It depends on the file: documents with little or no images only shrink slightly from the archive repacking, while ones with embedded JPEG photos can shrink significantly if you lower the quality slider.

Question 4

Is there a file size limit?

Accepted Answer

Files above roughly 150 MB aren't processed, since unpacking and repacking a very large archive in one pass can make the tab unresponsive.

Question 5

Does it remove the embedded document thumbnail?

Accepted Answer

Yes, the small preview thumbnail Office embeds is dropped — Office regenerates it automatically next time the file is saved.

Document Compressor

How to use it

Frequently asked questions

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