Slim your presentations.
Compress Keynote and PowerPoint files online. Free, fast, and secure.
Keynote
Compress Apple Keynote presentations
Up to 70% smallerPowerPoint
Compress Microsoft PowerPoint files
Up to 60% smallerTwo formats. One tool.
Deep image compression for the most popular presentation formats.
Keynote (.key)
- Converts internal PNG, TIFF, HEIC to optimized JPEG
- Updates Apple’s proprietary IWA binary references
- Handles nested Index.zip and Snappy compression
- Preserves images with alpha transparency
- Typical reduction: 30–70%
PowerPoint (.pptx)
- Converts PNG, TIFF to optimized JPEG inside ppt/media/
- Updates XML references and Content_Types automatically
- Preserves images with alpha transparency
- Compatible with Office 365, Google Slides, and LibreOffice
- Typical reduction: 30–60%
Why SlimKey?
Works from any browser
No Mac, no Windows, no installation. Compress presentations from any device with a browser.
Smart image optimization
Images are re-encoded to optimized JPEG at your chosen quality level. Transparency is preserved.
Non-destructive
Your original file is never modified. SlimKey always creates a new compressed copy.
Built for sharing
Smaller files fit within email limits, sync faster to cloud, and save disk space.
Frequently Asked Questions
Which file types does SlimKey support?
SlimKey supports Apple Keynote (.key) and Microsoft PowerPoint (.pptx) files. Each format has a dedicated compressor optimized for its internal structure.
How much smaller will my file be?
Typical reductions range from 30% to 70% for Keynote files and 30% to 60% for PowerPoint files, depending on the number and type of images. Files with many high-resolution photos see the biggest improvements.
Is it free?
Yes, SlimKey is completely free. No account, no signup, no hidden fees.
Is my file safe?
Your file is processed on our server and automatically deleted after download. We never store, share, or access your presentations.
Will my slides look different?
No. SlimKey carefully updates all internal file references so your presentation opens and looks exactly the same. The only difference is the file size.
SlimKey is the easiest way to compress presentation files online. Whether you use Apple Keynote or Microsoft PowerPoint, SlimKey optimizes your images intelligently \u2014 converting to JPEG where possible while preserving transparency where needed. Free, private, and no signup required.