How to Compress Files Before Sharing (And When Not To)

Zipping a folder before you upload it feels like a good habit, and sometimes it is — but compression doesn't help every file type, and for some of the files people share most often, it barely does anything at all.

When compression actually helps

Text-based and uncompressed formats shrink dramatically: documents, spreadsheets, plain text, source code, and vector/CAD files routinely compress by 50-90%. Bundling a folder of many small files into one zip also helps for a different reason — it turns a messy multi-file upload into one file and one link.

When compression barely helps

Photos (JPEG), video (MP4/MOV), and audio (MP3) are already compressed internally by their own format. Running them through a zip again typically saves only a few percent, sometimes nothing, and costs you the time it took to compress and the time the recipient spends extracting. RAW photo and video formats are the same story — they already use internal compression designed specifically for that data.

How to actually compress a folder

• Windows: right-click the folder → Send to → Compressed (zipped) folder.
• Mac: right-click the folder → Compress.
• Either way, check the result before uploading — the file size converter is a quick way to see exactly what you ended up with.

Compression vs. just using a bigger free limit

A lot of the reason people compress files is to squeeze under a small upload cap somewhere else. With a 50GB free limit and no account required, that pressure mostly disappears — compression stops being about fitting under a ceiling and becomes purely about cutting upload and download time. Use the transfer time calculator to see whether compressing a large file is actually worth the time it takes.

A quick rule of thumb

If the file is text, documents, code, or a pile of small files — zip it. If it's already photos, video, or audio — skip the zip and upload it as-is.