Common PowerPoint Presentation Mistakes (and How to Fix Them)

A PowerPoint presentation can make the delivery of your ideas clearer, more engaging and easier to follow. But if your slides are poorly planned or designed, they can just as easily distract from what you are trying to say.

Our academics work with students at all levels on PowerPoint presentations and often come across the same recurring issues: too much information, a lack of clear structure, inconsistent design and visuals that do not really add anything.

These problems are not limited to academic presentations. The same mistakes can affect anything from a university seminar or research talk to a workplace meeting, client pitch or conference presentation.

Below, we look at some of the most common PowerPoint presentation mistakes to avoid, whatever your subject or field, and what you can do instead.

1. Putting Too Much Text on Your Slides

One of the most common PowerPoint presentation mistakes is trying to fit too much written information onto each slide. This is particularly tempting when you are presenting a complex topic or have a lot of information to cover.

Let your slides support you

Your audience should not have to choose between reading your slides and listening to you. Keep what appears on screen focused on what you want them to notice or remember, such as:

You can then provide the detail verbally.

This is possibly the most recurrent mistake we see when helping undergraduate students with their presentations. Remember that, if there is information you want available as a prompt but do not need your audience to see, you can always use speaker notes in PowerPoint. They give you somewhere to keep reminders and additional detail without overcrowding the slide itself.

2. Trying to Include Everything You Know

When you have spent weeks, months or even years, in the case of PhD Viva presentations, working on a subject, deciding what to leave out can be difficult. You may want to provide all the background, explain every step of your reasoning or include every interesting finding.

Instead, be selective. Ask yourself:

What are the two or three points my audience needs to take away?
Which evidence best supports them?
How much background do they need?
What could be left for the Q&A?

This is especially important in academic presentations. If you have ten minutes to present a dissertation or research project, for example, you cannot simply turn every section of the written work into a slide. Focus on the central question, your approach and your most important findings.

Leaving something out does not mean you do not know it. Selecting the most relevant material is part of presenting a complex subject clearly.

3. Starting Without a Clear Structure

You can have ten individually strong slides and still end up with a confusing presentation if there is no clear connection between them.

Before worrying about fonts, colours or layouts, work out the story you are trying to tell.

Give your audience a route to follow

The precise structure will depend on whether you are presenting a research project, pitching an idea, reporting results or giving a conference talk. A research presentation, for example, might follow:

Context → Main question or problem → Key points/evidence → Conclusion

Whatever structure you choose, the progression should make sense. Simple signposting such as “I’ll now turn to the main findings” can also help your audience follow you.

To learn more about planning your content from beginning to end, see our guide on how to write a presentation with a clear structure.

4. Using Inconsistent Design from Slide to Slide

Your slides do not need to look identical, but they should look like they belong to the same presentation. Switching between fonts, heading sizes, colours and layouts can make a presentation look disjointed and distract from the content.

Creating visual consistency

Establish a few basic design rules and keep the following consistent:

5. Choosing Style Over Readability

A presentation can look impressive on your laptop and still be almost impossible to read from the back of a lecture theatre or conference room.

Small fonts are an obvious problem, but they are not the only one. Low-contrast colours, decorative typefaces, complicated backgrounds and text placed over busy images can all reduce readability.

Make sure your slides are accessible

Keep text large enough to read at a distance and choose colours that make it stand out clearly from the background. This is particularly important when slides are being projected onto a large screen, where colours and contrast may look different from how they appear on your laptop.

It is also worth thinking about accessibility when choosing your colours. The Web Content Accessibility Guidelines (WCAG) recommend a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. While these guidelines are primarily intended for web content, they provide a useful benchmark for checking whether your slides will be easy to read. A free tool such as the Coolors Contrast Checker can quickly tell you whether your chosen text and background colours have enough contrast.

And remember that readability is not only about colour. Leave enough space around text, images and other elements rather than trying to fill every available part of the slide. A simpler layout will often make your key points much easier to take in.

Ultimately, good PowerPoint design should direct attention towards your ideas, not towards the design itself.

6. Using Images Just to Fill Space

Images can make a presentation more engaging, but only when they serve a purpose. Adding a generic stock photo to every slide simply because it looks a little empty can end up creating visual clutter rather than improving the presentation.

Before adding an image, ask yourself: what does this visual help my audience understand?

A useful image might illustrate an unfamiliar concept, provide context, show an example or make a complex idea easier to grasp. In a research presentation, it could be a photograph of a site or object being studied; in a business presentation, it might show a product or provide context for the problem being discussed.
If an image does not add anything to the point you are making, you probably do not need it. Sometimes a simple slide with a few words and plenty of space is more effective.

Quality matters too. Avoid pixelated images, screenshots with unnecessary information around them or visuals stretched beyond their original proportions. And make sure you have permission to use the images you choose.

There are plenty of places to find high-quality images for presentations, including free image libraries, paid stock websites and specialist sources.

7. Making Charts and Data Too Complicated

A detailed chart may contain everything you want your audience to know, but that does not necessarily make it a good presentation slide.

This is a common presentation pitfall with research, survey results and other data-heavy material. A graph designed to be studied closely in a report or research paper may be difficult to understand in the few seconds an audience has to look at it.

Focus attention on the finding

Think about the main point your audience needs to take from the data. You could:

The same applies to tables. Detailed data can always be provided separately or as a handout; your slide only needs what is necessary to support the point you are making.

8. Overusing Animations and Transitions

PowerPoint and other presentation tools such as Canva and Prezi offer plenty of ways to make text fly, spin, fade and bounce onto the screen. You do not need to use all of them.

Too many animations and transitions can become distracting and make a presentation feel less polished.
That does not mean you should avoid them altogether. An animation can be useful for revealing a process in stages or introducing parts of a diagram as you explain them.

The test is whether it helps control the flow of information. If it is purely decorative, a simpler transition will usually work better.

9. Reading Directly from Your Slides

If everything you plan to say is already written on the screen, your audience has very little reason to listen to you say it again.

Reading slides word-for-word can make a presentation feel rehearsed in the wrong way. It also reduces eye contact and often leads to a flatter delivery because your attention is fixed on the screen rather than the people in front of you.

Your slides should provide the framework; you provide the explanation.

This is another reason to keep slide text concise. A few key points can remind you what comes next without turning the slide into a script. Speaker notes can hold additional prompts if you need them, while still allowing you to speak more naturally.

Of course, knowing what you want to say is only one part of presenting well. Pace, eye contact, body language and how you use your voice all influence how your message comes across. For more practical advice on these areas, see our guide on how to deliver a good presentation.

10. Not Practising with a Timer

You may know your presentation is supposed to last ten minutes, but you will not know whether it actually does until you practise it out loud.
A timed rehearsal may reveal that one section takes too long, you have too many slides or some explanations are repetitive.

If you are over the limit, do not simply speak faster. Look at what you can remove or simplify.
This is particularly important for assessed presentations, conference talks and research presentations, where the time limit may be fixed.

11. Neglecting Your Opening and Conclusion

The middle of a presentation often gets most of the attention, but a weak beginning or abrupt ending can undermine an otherwise strong presentation.

Your opening should quickly establish what you are going to talk about and give your audience a reason to pay attention. Avoid lengthy introductions or background information, but do not launch immediately into technical detail without context either.

There are many ways to start a presentation effectively. You might introduce a problem, share an interesting finding, provide brief context or explain the central question you will address.

Your conclusion deserves the same attention. Rather than ending abruptly, return to your main message and briefly draw together the most important points.

12. Forgetting Who You Are Presenting To

One of the easiest presentation mistakes to overlook happens before you start designing your slides: not thinking carefully enough about your audience.

A presentation for people who already know your subject should look and sound different from one intended for newcomers. Background information, terminology and the complexity of your explanations should reflect what your audience is likely to know.

This is particularly important with specialist material. A researcher speaking at a conference in their field can assume more background knowledge than when explaining the same project to students or the general public.

The format matters too. A classroom presentation, client pitch, conference talk and PhD viva all involve different audiences and expectations.

Quick Checklist Before You Deliver Your Presentation

Before you present, ask yourself:

Final Thoughts

A strong PowerPoint presentation does not need elaborate graphics or dozens of slides. Focus on what your audience needs to know, give your ideas a clear structure and use your slides to support rather than compete with what you are saying.

Most importantly, review and rehearse your presentation. Many avoidable presentation mistakes become much easier to spot once you practise delivering it.

Frequently Asked Questions

How many slides should a PowerPoint presentation have?

It depends on your time limit, subject and how much information each slide contains. Rather than aiming for a particular number, make sure you have enough time to explain every slide properly.

What is the 10-20-30 rule for PowerPoint?

The 10-20-30 rule, popularised by Guy Kawasaki, suggests using 10 slides, presenting for 20 minutes and using a minimum 30-point font. It was developed for business pitches, so it is not a strict rule for every presentation, but its emphasis on concise, readable slides can still be useful.

Should every PowerPoint slide include an image?

No. Images should serve a purpose. A photograph, diagram, chart or illustration can help explain an idea, but a simple text-based slide may sometimes communicate your point more clearly.

How much text should you put on a PowerPoint slide?

There is no fixed amount. Avoid long paragraphs and include only the text your audience needs to see. You can explain the detail verbally.

Is it better to use a PowerPoint template or create your own?

Both can work. Templates can save time and help maintain visual consistency, but make sure the design suits your content, is flexible enough for your needs and remains easy to read.