Why is my PowerPoint file so big?

Usually pictures inserted straight from a phone or camera, which PowerPoint keeps at full size however small they are shown, and pictures that were cropped or deleted but are still stored in the file. Embedded video and fonts add a lot too. Open "What took the space" after compressing to see which it is for your file.

Will the pictures look worse?

At the balanced setting a picture keeps 150 pixels for every inch it is shown, which looks sharp on screens and projectors; print quality keeps 220. A picture is only re-saved when that makes it smaller, and pictures with transparency stay PNG. Choose print quality for anything that will be printed large.

Does it work with macro-enabled .pptm, .docm and .xlsm files?

Yes. The macro project (vbaProject.bin) is copied unchanged, byte for byte, so macros keep working and a digital signature on them stays valid. The file keeps its macro-enabled type. A digital signature on the whole document (File › Info › Protect › Add a Digital Signature) is different: it covers every byte of the file, so it shows as invalid on the compressed copy, and the page says so - sign the copy again.

What about video in my presentation?

Video and sound are left exactly as they are; re-encoding them is not done here. If a video is most of the size, PowerPoint's own File › Info › Compress Media can shrink it, or convert it with the Video Converter and insert it again.

Is my presentation uploaded anywhere?

No. The file is unzipped, its pictures re-saved and the file zipped again by JavaScript in this browser tab. Nothing is sent anywhere, so confidential decks and reports are safe to compress here.

Why did my file not get smaller?

Its pictures may already be the right size, or it is mostly video, fonts or embedded files, which are left alone. Older .ppt, .doc and .xls files are not read here: saving one as .pptx, .docx or .xlsx in Office usually halves it on its own.

Stays on your computer How this works

Compress PowerPoint, Word and Excel files - free, no upload

Make a .pptx, .docx or .xlsx small enough to email: oversized pictures are scaled to the size they are shown and re-saved, leftover media is removed, and the file is zipped tighter. Slides, text and macros stay as they are. Nothing is uploaded.

SettingsPictures Save PNG pictures without transparency as JPEGRemove pictures and media nothing in the file usesRemove the preview thumbnailRemove custom document properties

Drag & drop PowerPoint, Word or Excel files here, or browse

.pptx, .docx, .xlsx and their macro (.pptm, .docm, .xlsm) and template kinds · several at once · up to 500 MB each · nothing is uploaded

About this PowerPoint compressor

Compress PowerPoint presentations, Word documents and Excel workbooks that are too big to email or upload. Almost always the size is pictures: a phone photo of 4,000 pixels shown a few inches wide on a slide. Each picture is scaled to what its largest use on a slide or page needs at the quality you pick, and saved again only when that makes it smaller; pictures left over from editing that nothing uses any more are removed; and the file is zipped again at the strongest setting. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

The slides, text, charts, animations, transitions and layout are not changed. Macros in .pptm, .docm and .xlsm files are copied byte for byte and keep working; embedded video and sound, fonts and embedded files are left as they are. To shrink a PDF instead, use Compress PDF; to turn a presentation into a PDF, PowerPoint to PDF.

What you can do

Compress .pptx, .docx and .xlsx files, and the macro-enabled .pptm, .docm and .xlsm, shows (.ppsx) and templates (.potx, .dotx, .xltx)
Scale pictures to the size they are shown, at 96, 150 or 220 pixels per inch, allowing for cropped pictures
Re-save JPEG pictures at a sensible quality, and PNG pictures with no transparency as JPEG
Remove pictures and media no slide, page or sheet uses any more
Optionally remove the preview thumbnail and custom document properties
See what took the space - pictures, video, fonts, embedded files - before and after
Compress several files at once, and save them one by one or together in a ZIP
Macros, video, sound, fonts and embedded files are never changed

How to compress a PowerPoint file

Choose how sharp the pictures need to be: smallest for email, balanced for screens and projectors, or print quality.
Drop your .pptx files (or Word and Excel files) on the page, or press browse.
Each file is compressed straight away; open "What took the space" to see where the size went.
Press Save for each file, or Save all as ZIP. The compressed copy is named "(compressed)"; your original is untouched.

Questions

Why is my PowerPoint file so big?: Usually pictures inserted straight from a phone or camera, which PowerPoint keeps at full size however small they are shown, and pictures that were cropped or deleted but are still stored in the file. Embedded video and fonts add a lot too. Open "What took the space" after compressing to see which it is for your file.
Will the pictures look worse?: At the balanced setting a picture keeps 150 pixels for every inch it is shown, which looks sharp on screens and projectors; print quality keeps 220. A picture is only re-saved when that makes it smaller, and pictures with transparency stay PNG. Choose print quality for anything that will be printed large.
Does it work with macro-enabled .pptm, .docm and .xlsm files?: Yes. The macro project (vbaProject.bin) is copied unchanged, byte for byte, so macros keep working and a digital signature on them stays valid. The file keeps its macro-enabled type. A digital signature on the whole document (File › Info › Protect › Add a Digital Signature) is different: it covers every byte of the file, so it shows as invalid on the compressed copy, and the page says so - sign the copy again.
What about video in my presentation?: Video and sound are left exactly as they are; re-encoding them is not done here. If a video is most of the size, PowerPoint's own File › Info › Compress Media can shrink it, or convert it with the Video Converter and insert it again.
Is my presentation uploaded anywhere?: No. The file is unzipped, its pictures re-saved and the file zipped again by JavaScript in this browser tab. Nothing is sent anywhere, so confidential decks and reports are safe to compress here.
Why did my file not get smaller?: Its pictures may already be the right size, or it is mostly video, fonts or embedded files, which are left alone. Older .ppt, .doc and .xls files are not read here: saving one as .pptx, .docx or .xlsx in Office usually halves it on its own.