Compressing files on Windows 10 can mean two things: packing files into a smaller ZIP file that’s easy to email or upload, or using Windows’ built-in drive compression to save disk space while keeping files usable in place. Both are built into Windows 10 and take seconds. This guide covers both, plus how to get smaller files with free tools and when compression doesn’t help.
Quick Answer
To make a ZIP file, select the files or folder in File Explorer, right-click, and choose Send to > Compressed (zipped) folder. To save disk space without zipping, right-click a folder, choose Properties > Advanced, and check Compress contents to save disk space.
Method 1: Create a ZIP File
- Open File Explorer and select the files or folder. Hold Ctrl to select several files.
- Right-click the selection and choose Send to > Compressed (zipped) folder. (Or use Share > Zip on the File Explorer ribbon.)
- A new .zip file appears in the same folder. Type a name and press Enter.
To add more files later, drag them onto the ZIP file. To open it, double-click to browse, or right-click and choose Extract All.
Method 2: NTFS Compression (Save Disk Space)
This compresses files on your drive but keeps them working normally; Windows decompresses them automatically when you open them.
- Right-click a folder (or file) and choose Properties.
- On the General tab, click Advanced.
- Check Compress contents to save disk space and click OK.
- Click Apply, choose Apply changes to this folder, subfolders and files, and click OK.
Compressed files show two blue arrows on their icons. This works only on NTFS drives, may slightly slow access to large files, and isn’t recommended for folders with frequently changing files or for the Windows folder itself. For system-wide savings, advanced users can run compact /compactos:always in an admin Command Prompt.
Method 3: Smaller Archives With 7-Zip
Windows’ ZIP compression is basic. The free 7-Zip (7-zip.org) can create smaller .7z files and password-protected, encrypted archives:
- Install 7-Zip.
- Right-click the files and choose 7-Zip > Add to archive (on Windows 11, under Show more options).
- Choose 7z or zip, set Compression level to Ultra, and optionally enter a password with AES-256 encryption.
- Click OK.
When Compression Doesn’t Help Much
JPG photos, MP4 videos, MP3 music, PDFs with images, and existing ZIP files are already compressed, so zipping them barely reduces their size. To shrink these, reduce the quality or resolution instead: resize photos, export videos at a lower bitrate, or use a PDF compressor. Text files, spreadsheets, and uncompressed images (like BMP) shrink the most.
Email Large Files
Most email services limit attachments to around 20–25 MB. If your ZIP is still too large, upload it to OneDrive or Google Drive and share a link, or split it into parts with 7-Zip (Split to volumes option).
Summary
- ZIP files: right-click > Send to > Compressed (zipped) folder.
- Save disk space: Properties > Advanced > Compress contents to save disk space.
- Use 7-Zip for smaller or password-protected archives.
- Photos and videos shrink more by lowering quality than by zipping.
Related: Make a Word document smaller.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.