Tips when using empower and large file sizes (20MB+) with OneDrive, SharePoint, or co-authoring

Working with large PowerPoint files stored in cloud platforms like Microsoft OneDrive and Microsoft SharePoint can quickly become slow and frustrating — especially when using co-authoring and AutoSave.

Saving a PowerPoint file on your computer's local drive is like dropping a barbell at your feet — gravity does the work, the floor catches it, done. Saving the same file to SharePoint or OneDrive is like having to clean and jerk it overhead, then carry it across the gym, then rack it on a specific hook that's just slightly out of reach.

The weight of the file is the same, but the path the computer has to move it through is completely different. Locally, the bar travels six inches. To the cloud, it has to be lifted (read from disk), pressed overhead (encrypted), walked across the gym (uploaded through your network), and then carefully placed on the rack (written to SharePoint's storage, version-controlled, indexed, and synced back down to confirm it landed properly).

Now make the barbell heavier — a 200MB deck full of embedded images and videos instead of a 5MB text-only one. Locally, your legs barely notice. But carrying it across the gym? Every extra kilo compounds. Your network is the weakest link in the chain — your hard drive can move data at gigabytes per second, but your upload speed is maybe 50-100 Mbps on a decent connection. That's the difference between deadlifting in your garage and farmer's-walking a loaded bar up three flights of stairs.

And here's the part that makes cloud saves feel disproportionately painful: SharePoint doesn't just catch the bar — it inspects it. Every save triggers versioning, co-authoring checks, permissions validation, and a sync confirmation. It's not just lifting the weight, it's lifting it under the eye of a judge who has to approve your form before the rep counts.

So a 5MB deck locally? A warm-up set. A 200MB deck to SharePoint? A loaded yoke walk with three checkpoints. Same lifter, same intent — wildly different effort because of where the weight has to end up and what has to happen along the way.

How can you tell what your file size is within PowerPoint? Our first video helps you learn how as well as gives you a basic understanding of what is within your file;

Now lets look at how empower can help keep the weight off your PowerPoint files

1. empower features and considerations when working with large PowerPoint file sizes

a. We start with our most important tip, keeping your file size as small as possible, whilst keeping the quality you need, is key..

empower 9.10 introduced a tool you will want to use for EVERY PowerPoint file with images; the fantastic File Size Inspector. This tool enables users to quickly scan all the images in a PowerPoint file and identify and reduce their file size within minutes. Click on the image below to learn more

b. Optimize Images & Media

c. empower performance tweaks 

empower may also be doing more than is needed when working with large filesizes. In this video we review empower's offline sync tool, to help ensure it is functioning correctly and reduce network traffic.

d. empower Chart Settings and Excel links

If your large PowerPoint file contains empower Charts, in the video below we explain how two empower settings that can help with larger documents, especially when you use multiple empower Chart links. First, I show chart user settings with preload charts, and I recommend not preloading in very large documents because it will take longer to open since it activates each chart. Second, in the Excel link manager I explain auto refresh on open versus manual refresh, and note you may need to wait while all linked objects update. I recommend setting auto refresh only for the specific charts or slide objects you actually need.

e. empower Agenda Update Settings

If your large PowerPoint file contains an empower Agenda, depending on the settings you use for this agenda, it might also affect system performance. If you have it set up to automatically update a simple action such as adding or moving slides will trigger an autosave as well as an empower update. Watch below how to decide the best settings for you.

 

2. Tips in general for all files

a. Slow down when selecting objects in PowerPoint. Really, this does actually help...

When you're rapid-firing clicks to select shapes on a slide, your mouse is moving faster than PowerPoint can keep up with. You click, you're already moving to the next shape, you click again — but somewhere in that sequence the app misses the "let go" between clicks and reads your movement as a drag instead of a selection. The result: the shape you just grabbed shifts a pixel. Or ten pixels. Or across the slide if you were really flying.

On a local file, this is annoying but cheap. Hit Ctrl+Z, the shape snaps back, you carry on. On SharePoint or OneDrive with autosave on, it's a different story. Every nudge — even one you didn't mean to make — is a save event. The file gets packaged up, encrypted, shipped to the cloud, version-stamped, and synced back. On a heavy deck, that round trip takes long enough that your next clicks land in a frozen or laggy window, which causes more accidental drags, which causes more saves. You're now fighting the file instead of editing it.

Counterintuitively, slowing your clicks down by a fraction of a second is faster overall. Give PowerPoint enough time to register each click as a discrete event — select, release, move, select, release — and it correctly builds up a multi-shape selection without interpreting any of it as a drag. You lose maybe 200ms per selection and save yourself the undo-redo-wait-resync loop that costs ten times that.

This is genuinely a Microsoft deficiency — the input handler should be more forgiving of fast clicks — but it's made dramatically worse by everything else your machine is juggling in the background. Teams syncing, Outlook indexing, OneDrive reconciling, antivirus scanning the very file you're editing. Every one of those is competing for the same CPU cycles PowerPoint needs to process your clicks cleanly. You don't see any of it, but your shapes feel it.

b. Simplify Slide Masters

We see this constantly. A user's template has maybe four slides, but the file is 80MB. Almost always, the culprit is something buried in the slide master — a high-res background image, a logo at 10x the resolution it needs to be, occasionally even a video that nobody remembers putting there.

Here's why that matters: anything sitting on the master gets carried into every single presentation built from that template. It's not a reference, it's a passenger. You're lifting it on every save, every open, every sync — and you can't see it in the normal slide view, so nobody knows it's there.

Worse, the weight travels. Paste a slide from that template into another deck with "Keep Source Formatting," and the bloated master comes along for the ride. Now a clean 5MB deck is suddenly 50MB because one borrowed slide brought its entire gym bag with it.

Overcomplicated templates don't just slow down the file they live in — they infect every deck that touches them. Fix the master once, and you fix the weight problem everywhere downstream.

3. Tips when working on the same file with colleagues (co-authoring)

a. Structure collaboration intentionally

Unfortunately, large PowerPoint files (50mbs and over), and PowerPoint files with a lot of slides (50+) when combined with using co-authoring all to often result in performance challenges. This is because to co-author PowerPoint files you must be working in OneDrive or SharePoint and have the Auto-save option enabled. This means any action by any user will need to be saved, and sync for it to reflect on each users machine. If the file is large, and there are many users working in the file at the same time this can quickly snowball. Our recommendations are

• Assign clear ownership of slides or sections. Consider assigning one team member as the designated editor to reduce the number of edits the network must process as much as possible.

• Avoid multiple people editing the same slides at once

• Use PowerPoint sections to divide work logically

Why it this matters: working in this way reduces syncing conflicts and improves responsiveness.

b. If you have a choice, always choose working in the Desktop App

If possible, avoid co-authoring large files in the browser. The Desktop App is set up to cache auto-save changes locally and sync at the best possible moment for the network. The Browser version is live for all users and therefore must save changes at the source.

Best practice:

• Open files in the PowerPoint desktop application

• Sync files locally via OneDrive

• Avoid PowerPoint Online for heavy editing

Why it matters: The desktop app handles memory, rendering, and large assets far more efficiently.

c. Control “Heavy” Editing Actions

Some actions are particularly resource-intensive. Especially some of the empower features, which are great when used in context, but if you are co-authoring a 60 slide presentation and decide to translate all of the slides whilst your team are also editing, prepare to be unpopular with your team.

Examples:

• Editing Slide Master. These changes will affect all of your users and can often be in ways they do not expect as their formatting may change markedly. Not much fun when you aren't expecting it.

• Replacing fonts. Another bulk change that will affect all slides if done throughout a file

• Bulk formatting changes

• Moving large groups of slides

Best practice:

• Only one user performs these actions at a time, and before your co-author/sharing session.

Why it matters: Prevents lag, conflicts, and potential file instability.

4. Tips for working with OneDrive & SharePoint

a. Manage AutoSave Strategically

AutoSave in theory is helpful, but depending on the situation it is sometimes more helpful to use it sparingly.

Best practice:

• Turn AutoSave OFF during heavy editing (e.g. image updates, layout changes)

• Turn it back ON once changes are complete

Why it matters: AutoSave triggers constant syncing, which slows performance in large files.

b. Be mindful of Versioning

OneDrive, SharePoint and other Cloud platforms allow the ability to roll-back to numerous save points in a files lifecycle. Great for recovering work, but also a network intensive tasks if they create frequent versions automatically.

Best practice:

• Avoid excessive micro-edits across multiple users

• Create clear checkpoints for major updates

Why it matters: Keeps version history clean and reduces unnecessary processing.

c. Work Locally, Sync Periodically

Consider the advice on AutoSave and versioning above. If you experience painful editing online, then consider taking the bulk of editing offline and then upload when you really need to. 

Best practice:

• Work locally on synced files

• Save intentionally (not constantly)

• Allow time for files to fully sync before closing

Why it matters: Reduces background activity and improves responsiveness.

d. Consider Splitting Large Files

Sometimes, one file is simply too large. See the section 2 above for tips for individual slides which are making your files much bigger than they need to be. Otherwise consider these points;

Best practice:

• Break presentations into smaller sections or modules

• Combine only for final delivery

Why it matters: Smaller files are faster, more stable, and easier to collaborate on.

e. Ensure Strong System & Network Performance

Best practice:

• Close unnecessary applications and browser tabs

• Use a stable internet connection (preferably wired)

• Avoid VPNs where possible

• Use 64-bit PowerPoint if available

Why it matters: Large files require both system memory and stable connectivity.

Key Takeaway

PowerPoint can handle large, collaborative files — but only with the right approach. Treat collaboration as structured and semi-synchronous, not fully real-time. This ensures better performance, fewer issues, and a smoother user experience.

For further guidance or tailored setup support, contact your empower^® Express team.