Free tools · no sign-up
Tools for the deck you’re building.
What free tools help you build a better presentation?
Four checks cover most of what goes wrong in a deck: a slide-count calculator that turns a talk length into a slide and word budget, a contrast checker that tests every colour pairing a slide renders, a rehearsal timer that compares your pace against slide position, and a reference for standard slide dimensions.
Slide Count Calculator
Work out how many slides a talk of any length needs — and how many words each one can carry.
Open toolPresentation Contrast Checker
Check every colour pairing a slide actually uses — including the ones on cards, where palettes usually fail.
Open toolPresentation Timer
Rehearse against the clock, and see which slide you should be on right now.
Open toolSlide Size Guide
Every standard slide dimension in pixels, inches and centimetres — plus which to use where.
Open tool
What each tool answers
- How many slides do you need for a presentation?
- A 10-minute presentation typically needs 10 to 12 slides, at roughly 50 seconds per slide. Pitches run faster, near 30 seconds a slide; training sessions run slower, near 90. The tighter constraint is words: a slide should carry about 18% of what is spoken over it, or the audience reads instead of listening.
- Slide Count Calculator →
- What contrast ratio do presentation slides need?
- Presentation body text needs a contrast ratio of at least 4.5:1 against its background, and large headings and non-text marks such as icons, rules and chart bars need at least 3:1. These are the WCAG 2.2 AA thresholds. Palettes most often fail on tinted surfaces rather than on the slide itself.
- Presentation Contrast Checker →
- How do you use a timer to rehearse a presentation?
- Set the timer to your speaking slot and enter your slide count, then rehearse from the start without stopping. Dividing the slot by the slide count gives a target pace, so comparing the slide you are on with the slide you should be on shows whether you are ahead or behind while there is still time to correct.
- Presentation Timer →
- What size is a PowerPoint slide?
- The default PowerPoint and Google Slides size is 16:9 widescreen, which is 13.333 by 7.5 inches, or 33.87 by 19.05 centimetres. The older 4:3 standard is 10 by 7.5 inches. Exported at 1080p, a 16:9 slide is 1920 by 1080 pixels; social carousels use 1080 by 1350 for portrait and 1080 by 1080 for square.
- Slide Size Guide →
Frequently asked questions
Are these presentation tools free?
Yes. All four run in the browser with no account, no sign-up and no usage limit. Nothing you type is sent anywhere — the calculations happen on your own device.
Do I need to create an account?
No. The tools are static pages with the logic running locally in your browser. An account is only needed if you go on to generate a deck with Slideso.
Do the tools work offline?
Once a tool page has loaded, yes. Every calculation runs in your browser rather than on a server, so the page keeps working if the connection drops.
Which tool should I start with?
The slide count calculator, before you build anything. Slide count and words per slide are decisions that are cheap to make first and expensive to change once a deck exists.
Do these work for Google Slides and Keynote as well as PowerPoint?
Yes. Slide counts, pacing, contrast ratios and dimensions are properties of the presentation rather than the software. The slide size guide lists the defaults for each.
Or skip the checklist
Slideso applies all four checks while it builds: pacing from your slide count, contrast enforced by the layout engine, and a canvas sized correctly before the first slide is drawn.
Generate a presentation →