Free tool
Compress PowerPoint
Shrink an oversized .pptx so it fits in an email. It compresses the photos and pictures that are making the file heavy and leaves your text, charts and layout completely alone. Prefer to do it inside PowerPoint? The steps are further down.
Free, no account. Your file is deleted right after it is compressed.
How to compress a PowerPoint file online
- 1
Upload the deck
Drag your .pptx onto the box above. Nothing is uploaded until you press compress.
- 2
Pick how hard to squeeze
Balanced is right for almost every deck. Go stronger only when there is a hard attachment limit to clear.
- 3
Download the smaller file
You get the same deck back, still fully editable, with the images re-encoded at a size a slide can actually display.
How to compress pictures in PowerPoint
PowerPoint has this built in, and for many decks it is all you need — no upload, no third party. Here is the real route, followed by the cases where it runs out.
Windows
- 1Click any picture on a slide. A Picture Format tab appears in the ribbon.
- 2In the Adjust group, click Compress Pictures.
- 3Untick “Apply only to this picture” — otherwise you are compressing one photo out of forty.
- 4Tick “Delete cropped areas of pictures”. Cropping in PowerPoint only hides the rest of the image; the pixels are still in the file.
- 5Pick a resolution: E-mail (96 ppi) for sending, Web (150 ppi) for presenting, Print (220 ppi) to keep print quality.
- 6Click OK, then save the file. Nothing is written until you save.
Mac
- 1Select a picture, then open the Picture Format tab.
- 2Click Compress Pictures.
- 3Set “Picture Quality” to the lowest setting you can accept, and choose “All pictures in this file”.
- 4Tick “Delete cropped areas of pictures”, then click OK and save.
When the built-in option is not enough
- It caps resolution but never changes format. A deck full of PNG screenshots is the most common cause of a huge file, and PowerPoint will leave every one of them as a PNG.
- It ignores embedded fonts entirely. If “Embed fonts in the file” was ever ticked, that is often several megabytes the dialog cannot see.
- Check File → Options → Advanced → Image Size and Quality first. If “Do not compress images in file” is ticked, the Compress Pictures dialog quietly does nothing.
- It edits your file in place. There is no before-and-after, and no undo once you have saved and closed.
- It is not available at all if you are working in PowerPoint for the web.
Why decks get so big, and what this fixes
Photos stored at camera resolution
A 6000-pixel photo dropped onto a slide is kept at 6000 pixels forever, even when it displays at a tenth of that. Resizing it to what the slide shows is where nearly all the saving comes from.
Screenshots saved as PNG
PNG is the wrong format for a photograph or a gradient-heavy screenshot. Images with no transparency are re-encoded as JPEG; anything with a transparent background stays PNG so cut-outs keep their edges.
Nothing is flattened
Your slides are not rendered to pictures. Text stays text, charts stay charts, animations and speaker notes survive, and the file you get back is still a deck you can edit.
Never returns something worse
Every image is kept only if the new version is genuinely smaller, and a deck with nothing left to gain comes back byte-for-byte unchanged rather than quietly degraded.
What to expect
No converter is lossless. These are the cases where the result will not match the original, stated up front rather than discovered on the file that mattered.
- Embedded video and audio are left untouched. They cannot be re-encoded safely here, and a deck that is mostly video will barely move.
- Vector artwork in EMF or WMF is passed through as-is. It is usually small, and re-drawing it is how other tools turn a crisp logo into a blur.
- Removing embedded fonts is optional and off by default. It is often the biggest single saving, and it is also the one change that alters how the deck looks on someone else's computer.
- A deck that is already optimised will report no saving. That is the honest answer, not a failure.
- Only .pptx works. The old binary .ppt format has to be saved as .pptx in PowerPoint first.
Questions people actually ask
Everything below describes what this compressor does today, not what a marketing page wishes it did.
Decks that were never bloated in the first place
Skiaw builds presentations with images sized for the slide they sit on, so the file you export is small before anyone has to compress it.