The fastest way depends on what kind of file you have

A file gets smaller when you remove data from it or compress the data so it takes up less space. Which method works depends on whether you're dealing with photos, videos, documents, or a folder full of mixed files. Photos and videos shrink the most when you reduce their dimensions or quality. Documents shrink when you remove images or embedded fonts. A folder of mixed files shrinks when you compress them into a single archive.

Your upload limit matters too. If a website says you can upload 25 MB and your file is 50 MB, you have to shrink it. If you're uploading to cloud storage with a 2 GB limit and your file is 100 MB, you might not need to shrink anything — but shrinking it anyway means it uploads faster and uses less of your storage quota.

Key Takeaways

  • Photos shrink fastest by opening them in Preview (Mac) or Photos (Windows), exporting as JPEG instead of PNG, and lowering the quality slider to 70–80 percent.
  • Videos shrink by lowering the resolution from 1080p to 720p or reducing the frame rate from 30 fps to 24 fps, which you can do in free tools like HandBrake.
  • Multiple files shrink by creating a ZIP archive, which you can do by right-clicking a folder and selecting "Compress" on Mac or "Send to > Compressed (zipped) folder" on Windows.
  • PDFs shrink by opening them in Preview (Mac) or using a free online tool, then exporting at lower resolution or removing embedded images.
  • You can check how much smaller a file got by right-clicking it, selecting Properties (Windows) or Get Info (Mac), and comparing the original size to the new size.

Shrinking photos without losing quality you'll notice

Photos take up the most space, and they shrink the most without looking bad. On a Mac, open the photo in Preview, click Tools, then Export. Change the format from PNG to JPEG if it isn't already — JPEG compresses photos much more than PNG does. Move the Quality slider to 70 or 75 percent. A photo that was 8 MB often becomes 1 to 2 MB. Open the new file and look at it full-screen. Unless you're printing it large, you won't see the difference.

On Windows, open the photo in the Photos app, click the three dots at the top right, select Edit, then click Save a copy. In the dialog that appears, lower the quality. Windows doesn't always show you a slider — instead you may see a list of preset sizes like "Medium" or "Small". Pick Medium first, save it, and check the result. If it's still too large, repeat with Small.

If you have dozens of photos to shrink, don't do them one at a time. On Mac, use a free tool like ImageOptim — drag your photos into it and it shrinks them all at once while keeping them in the same folder. On Windows, use FileOptimizer, which works the same way. Both tools are faster than opening each photo individually.

Reducing video file size

Videos are usually the largest files you'll encounter. A one-minute video shot on a phone can easily be 100 MB or more. The fastest shrink comes from lowering the resolution. A video recorded at 1080p (full HD) can be re-encoded at 720p and look nearly identical on a computer screen. The file size often drops by half.

read HandBrake, which is free and works on Mac, Windows, and Linux. Open your video in HandBrake, and in the right panel under Dimensions, change the Width to 1280 (which is 720p). Leave the Height blank so it adjusts automatically. Under Video, you can also lower the Frame Rate from 30 to 24 frames per second if the video doesn't have fast motion — this saves more space. Click Start Encode and wait. A five-minute video usually takes five to fifteen minutes to re-encode depending on your computer.

If you only need a clip from the video, not the whole thing, that's the biggest shrink of all. In HandBrake, use the Range section to set a start and end time, then encode only that portion. A 500 MB video becomes a 50 MB clip if you're only keeping ten percent of it.

Compressing multiple files into one archive

If you need to upload a folder with ten documents, five photos, and three spreadsheets, don't upload them one at a time. Create a ZIP archive instead. On Mac, right-click the folder and select Compress. On Windows, right-click the folder, hover over Send to, and click Compressed (zipped) folder. Both create a single .zip file that contains everything inside.

The ZIP file is usually 5 to 15 percent smaller than the original folder because ZIP removes some redundant data. More importantly, you can upload one file instead of eighteen. The person receiving it can open the ZIP file on any computer — Windows, Mac, or Linux — without installing anything.

If the ZIP file is still too large, you can split it. On Mac, use The Unarchiver (free, from the App Store) and look for a Split Archive option. On Windows, use 7-Zip (free, open-source) to create a multi-part archive. This creates several smaller files instead of one huge one, and the recipient can combine them back together.

Making PDFs smaller

A PDF can be large if it contains high-resolution images or embedded fonts. On Mac, open the PDF in Preview, click File, then Export. In the Quartz Filter dropdown, select Reduce File Size. Save it with a new name. The file usually shrinks by 30 to 50 percent.

On Windows, Preview isn't available, so use a free online tool like Smallpdf or ILovePDF. Upload your PDF, let it compress, and read the result. These tools are safe — they delete your file from their servers after a few hours. If your PDF contains sensitive information and you don't want to upload it, use a desktop tool like PDFtk (free, open-source) instead, though it requires more technical steps.

If your PDF has many high-resolution images and you don't need them to be high-resolution, you can also open it in Preview (Mac) or Adobe Acrobat Reader (Windows, free version), take a screenshot of each page, and create a new PDF from the screenshots. This is slower but produces a much smaller file.

Checking how much smaller your file got

After you shrink a file, verify the new size so you know whether it's small enough to upload. On Windows, right-click the file and select Properties. Look for Size or Size on disk. On Mac, right-click the file and select Get Info. Look for Size.

Compare the new size to the upload limit. If the limit is 25 MB and your file is now 18 MB, you're good. If it's still 30 MB, you need to shrink it more — try lowering the quality further, or if it's a video, lower the resolution more.

Keep the original file in case you need it later. Rename the smaller version with a suffix like "small" or "compressed" so you don't accidentally delete the original. For example, rename "family-video.mp4" to "family-video-720p.mp4".

When shrinking doesn't work enough

Sometimes a file is so large that shrinking it to an acceptable size means it looks noticeably worse. A video at 480p resolution looks grainy on a large monitor. A photo at 40 percent quality looks blurry. In these cases, you have other options.

Ask the person or service you're uploading to whether they have a higher limit, or whether they can receive files through a different method. Some websites let you upload via a cloud storage link instead of uploading the file directly — you upload to Google Drive or Dropbox, then share the link. Some services let you mail a USB drive or external hard drive instead of uploading at all.

If you're uploading to a website that won't budge on the limit, and shrinking makes the file unusable, you may need to split the content across multiple uploads. A 200 MB video can become two 100 MB videos if you split it at a natural break point. A folder of 50 photos can become five folders of 10 photos each.

Frequently Asked Questions

Will shrinking a photo or video damage it permanently?

No, as long as you keep the original. Always save the smaller version with a different name so the original stays untouched. If you shrink a photo to 60 percent quality and decide it looks too blurry, you still have the original to try again at 75 percent.

What's the difference between compressing a file and creating a ZIP archive?

Compressing a photo or video removes data to make it smaller — you can't undo it without the original. A ZIP archive bundles files together and removes some redundant data, but the original files are still inside unchanged. You can extract them and they'll be exactly as they were.

Can I shrink a file after I've already uploaded it?

Not on the website itself — you have to shrink it on your computer first, then upload the smaller version. If you've already uploaded a large file and want to replace it with a smaller one, delete the original upload first, then upload the new smaller version.

Is it safe to use online tools to compress PDFs or videos?

Most well-known tools like Smallpdf and ILovePDF are safe and delete your files after a few hours. If your file contains sensitive information like tax returns or medical records, use a desktop tool instead so the file never leaves your computer.

How do I know if a file is small enough to upload?

Check the website's upload limit — it's usually shown near the upload button or in the help section. Right-click your file and check its size. If your file size is smaller than the limit, it will upload. If it's close to the limit, shrink it a bit more to be safe, since some websites count overhead.