The fastest way depends on what kind of file you have

The method that works best depends on whether you're compressing a photo, a video, a document, or a folder full of mixed files. Photos and videos shrink most when you reduce their dimensions or quality — a process called lossy compression because you lose some detail. Documents and spreadsheets shrink when you remove formatting or embed fonts, or when you use a compression tool that squeezes the data without losing anything — called lossless compression. A folder of files gets smaller fastest when you create a ZIP archive, which bundles everything together and compresses it all at once.

Start by checking the file size you're working with. Right-click the file (or Control-click on Mac), select Properties or Get Info, and look for the size in bytes, kilobytes, or megabytes. Then decide: do you need the original quality, or is smaller more important? That choice determines which tool to use and how much smaller you can make it.

Key Takeaways

  • Photos shrink fastest when you reduce their width and height in pixels, not just the file format — a 4000×3000 photo compressed to 2000×1500 can be one-quarter the size.
  • Videos need video editing software or an online converter to shrink noticeably; changing the file format alone rarely makes a big difference.
  • Multiple files compress best as a ZIP archive, which you create by right-clicking a folder and selecting "Send to" or "Compress" depending on your operating system.
  • Lossless compression (ZIP, 7-Zip, RAR) keeps every detail but shrinks less; lossy compression (JPEG for photos, MP4 for video) shrinks more but loses quality you cannot get back.

Shrinking photos without losing too much quality

Photos take up the most space, and they shrink the most when you make them smaller in pixels. Open the photo in any image editor — Windows comes with Photos, Mac comes with Preview, and free options include GIMP or Photopea (which runs in your browser). Look for a "Resize" or "Scale Image" option. If the photo is 4000×3000 pixels and you resize it to 2000×1500, the file size drops to roughly one-quarter of the original because you have one-quarter the total pixels.

After resizing, save it as a JPEG instead of PNG or BMP if you haven't already. JPEG uses lossy compression, which means it throws away some color information your eye probably won't notice. When you save, most editors let you choose a quality level from 1 to 100 — try 80 or 85 first. A photo at quality 85 looks nearly identical to the original on a screen but takes up half the space. If you need the photo for printing, keep it at 90 or higher; if it's only for email or a website, 75 to 80 works fine.

For a batch of photos, use free software like ImageMagick (command line, steeper learning curve) or XnConvert (graphical interface, easier). Both let you resize and re-save dozens of photos at once instead of one by one.

Compressing videos for upload

Videos are harder to shrink because they contain so much data. Changing the file format from MOV to MP4 or from AVI to MP4 usually makes little difference — the real size comes from the resolution and frame rate. A 1080p video (1920×1080 pixels) at 30 frames per second takes up far less space than a 4K video (3840×2160 pixels) at 60 frames per second, even in the same format.

To actually shrink a video, use free software like HandBrake (Windows, Mac, Linux) or Shotcut (Windows, Mac, Linux). Open your video file, then lower the resolution — try 720p (1280×720) if the original is 1080p, or 480p if you're uploading to a platform that doesn't need high quality. You can also lower the bitrate, which controls how much data the video uses per second; HandBrake's presets do this automatically. Export the file and compare the size to the original. A 1GB video might shrink to 200MB or 300MB depending on how much quality you're willing to lose.

If you're uploading to a platform like YouTube, Google Drive, or Dropbox, check whether they compress videos automatically after upload. If they do, you may not need to compress beforehand.

Creating a ZIP archive for multiple files

When you have a folder with many files — photos, documents, spreadsheets — the fastest way to make it smaller is to create a ZIP archive. This bundles all the files together and compresses them losslessly, meaning no quality is lost but the space savings are usually 10 to 30 percent depending on the file types inside.

On Windows, right-click the folder, hover over "Send to," and click "Compressed (zipped) folder." Windows creates a new ZIP file in the same location. On Mac, right-click the folder and select "Compress." On Linux, right-click and look for "Compress" or open the folder in your file manager and use the Archive menu.

The resulting ZIP file is what you upload. The person receiving it can open it by double-clicking on Windows or Mac, or by right-clicking and selecting "Extract" on any system. If the ZIP file is still too large, you'll need to compress the individual files inside it — resize photos, reduce video quality, or remove files you don't need.

Using dedicated compression software

If you compress files regularly, dedicated tools offer more control than the built-in options. 7-Zip (Windows, free) and The Unarchiver (Mac, free) create smaller archives than ZIP in many cases because they use more advanced compression algorithms. WinRAR (Windows, paid but has a free trial) offers similar features. These tools work the same way: right-click a file or folder, select the compression option, and choose your settings.

For photos specifically, tools like FileOptimizer (Windows, free) or ImageOptim (Mac, free) batch-process images and remove unnecessary metadata — information embedded in the file like the camera model or GPS location — without changing the visible image. This usually saves 5 to 15 percent of the file size and is useful if you're uploading dozens of photos at once.

When the file is still too large after compression

If you've resized photos, lowered video quality, and created a ZIP archive but the file is still too big, you have a few options. First, check whether the upload limit is a hard limit or a soft one — some services let you upload in chunks or split files across multiple uploads. Google Drive, for example, has a 5TB limit per file but you can upload multiple files.

Second, remove files you don't absolutely need. If a folder contains 50 photos and you only need 20, delete the rest before compressing. Third, use cloud storage to transfer the file instead of uploading directly. Services like Tresorit, Sync.com, or even a shared Google Drive folder let you upload large files and send a link to someone else, which often has higher limits than email attachments or form uploads.

Frequently Asked Questions

Can I compress a file multiple times to make it smaller?

No. Once you compress a file with lossy compression (like JPEG for photos), compressing it again won't make it noticeably smaller — you're just re-compressing the same reduced data. Lossless compression (ZIP) can compress an already-compressed file, but the second pass usually saves only a few percent more. Compress once, then stop.

Does changing the file name make it smaller?

No. The file name has almost no effect on file size. The size comes from the content inside the file — the pixels in a photo, the frames in a video, the text and formatting in a document. Renaming a photo from "IMG_001.jpg" to "a.jpg" saves only a few bytes.

What's the difference between ZIP and RAR?

Both are archive formats that compress files. ZIP is built into Windows and Mac, so anyone can open it without extra software. RAR compresses slightly better in some cases but requires WinRAR or another tool to open. For most uploads, ZIP is simpler because the recipient doesn't need to install anything.

Will compressing a file damage it?

Lossless compression (ZIP, 7-Zip) never damages a file — when you decompress it, you get back exactly what you started with. Lossy compression (JPEG, MP4) throws away data, so you lose some quality, but the file itself isn't damaged. Once you save a photo as JPEG at quality 80, you cannot get back the detail you lost by re-saving it at quality 100.

How much smaller can I make a file?

It depends on the file type. Photos can shrink to 10 to 30 percent of their original size by resizing and changing to JPEG. Videos can shrink to 20 to 50 percent by lowering resolution and bitrate. Documents and spreadsheets shrink 5 to 15 percent with ZIP compression. The more you're willing to lose quality, the smaller you can make it.