Best AI Add-ins for PowerPoint and Google Slides

If you already live in PowerPoint or Google Slides and want AI to help without making you learn a new app, you want an add-in, not a standalone maker. The three that matter are Plus AI, SlidesAI and Microsoft Copilot — and the right one depends almost entirely on which apps you use and whether you need to edit existing decks or just generate new ones. Plus AI is the most capable, SlidesAI is the cheapest with a free plan, and Copilot is the natural choice if you already pay for Microsoft 365. Here is how to tell them apart.

Why an add-in instead of a standalone maker

Standalone tools like Gamma or Canva ask you to build your deck in their app and then export it. That export is where things go wrong: formatting shifts, fonts change, and sometimes you get flat images instead of editable slides. An add-in avoids the problem entirely by working inside the app you already use, so the output is a native, editable PowerPoint or Google Slides file from the start — there is no export step to lose fidelity in.

If your organisation mandates PowerPoint, or you collaborate in Google Slides, an add-in keeps you in that world while adding AI generation on top. That is the whole case for this category.

There is a second, quieter advantage: you keep everything you already rely on in the host app. Real-time collaboration, comment threads, version history, your company template, the sharing permissions your IT team set up — all of it still works, because your deck is a normal Slides or PowerPoint file that happens to have been drafted by AI. A standalone maker asks you to give up that ecosystem and adopt its own; an add-in asks you to give up nothing.

The three add-ins at a glance

Details change — confirm on each vendor's own site before buying.

Plus AI — the most capable add-in

Plus AI is the one to beat. It works in both Google Slides and PowerPoint (and Google Docs), so it fits almost any workflow, and its output is native and fully editable with no export step.

Its real standout, though, is something most AI tools cannot do at all: it edits existing decks. Plus AI can insert, remix and rewrite individual slides inside a deck you already have. Every generate-from-scratch tool can make you a new deck; very few can improve the one you already made. If your actual job is maintaining and updating decks — a sales team keeping a pitch current, an agency refreshing client decks — this is the feature that justifies the subscription on its own.

The catches: there is no free plan, only a 7-day trial that wants a card; generation is credit-metered until the $200 Max tier; and the brand kit lives on the $30 Team plan. And because it works inside your host app, its design ceiling is that host app's ceiling — you get better PowerPoint, not Gamma-style flair.

Choose Plus AI if: you edit and maintain decks as much as you create them, you use both Slides and PowerPoint, and you will pay for the capability.

SlidesAI — the cheap, simple, free-to-try option

SlidesAI is the lightweight choice: paste in text — notes, an article, a topic — and it builds a deck inside Google Slides or PowerPoint. It does not try to do everything, and that focus is its strength. It has a genuine free plan (12 presentations a year), a low $10 entry price, and one of the largest install bases in the category.

The trade-off is depth. SlidesAI generates a first draft well but is thin on editing existing decks and on brand controls, and its plans are metered in whole presentations per year with a character cap — a limit that pinches frequent users. It is a text-to-slides generator, not a full AI assistant.

Choose SlidesAI if: you want the cheapest way to turn text you already have into a starter deck, you are an occasional user, or you simply want a free plan to try the add-in idea before committing.

Microsoft Copilot — the natural pick if you already have Microsoft 365

Microsoft Copilot for PowerPoint is AI built directly into PowerPoint. Because it is PowerPoint, its output is native, editable, watermark-free .pptx with the deepest possible integration into your real templates and — in the business version — your organisation's own data through Microsoft Graph. It builds decks from a prompt, a Word document, a spreadsheet or a PDF, and restyles existing slides too.

The catch is entirely about access. There is no free tier and no standalone product: you need a paid Microsoft 365 plan that includes Copilot. Microsoft's licensing here has been a moving target — the old standalone Copilot Pro was retired for new buyers in late 2025, consumer access now comes through Microsoft 365 Personal, Family or Premium, and business access is a per-user add-on. If you already pay for Microsoft 365, adding Copilot may be the lowest-friction AI you can get. If you are not in that ecosystem, the cost and complexity are hard to justify for presentations alone.

Choose Copilot if: you (or your company) already run on Microsoft 365, PowerPoint is your mandated format, and you want AI inside the app with no third-party tool at all.

Generating versus editing — the distinction that decides it

The single most useful way to choose among these is to ask what you actually spend your time doing. There are two very different jobs hiding under "make a presentation," and add-ins are not equally good at both.

Generating is starting from nothing: a prompt or a document goes in, a fresh deck comes out. All three tools do this well, and so, frankly, do the standalone makers. If generating is your whole need, price and host app decide it — SlidesAI if you want free or cheap, Copilot if you already own Microsoft 365.

Editing is improving something that already exists: rewriting a clumsy slide, restyling an inherited deck, inserting three new slides into a client's existing pitch. This is where Plus AI genuinely separates itself, because it was designed for the deck you already have rather than the one you are starting. Most tools quietly assume you begin from a blank prompt, and are little help once a deck exists. If a large part of your work is maintaining decks other people made — or your own, over time — that capability is worth more than any amount of generation speed.

A word on installing add-ins at work

One practical wrinkle that catches teams out: add-ins often need an administrator's blessing. In a managed Google Workspace or Microsoft 365 environment, IT may have to approve a Marketplace or AppSource add-in before you can install it, and some organisations restrict third-party add-ins for data-governance reasons. This is not a reason to avoid add-ins — it is a reason to check with whoever runs your workspace before you build a workflow around one. Copilot sidesteps this entirely for Microsoft shops, because it is a first-party Microsoft feature rather than a third-party add-in, which is part of its appeal to security-conscious organisations.

What it actually costs over a year

Because add-ins are cheap per month, the annual figure is easy to ignore — but it is worth a moment. SlidesAI's free plan is genuinely £0 for twelve decks a year, and its Pro tier is around $120 a year. Plus AI's entry tier is roughly $120 a year too, though heavy generators climb its credit tiers. Copilot has no separate line item if you already pay for Microsoft 365 — its cost is effectively zero on top of a licence you hold, which is the whole reason it is the default for Microsoft shops. Against a standalone maker, an add-in is usually the cheaper route to AI slides, because it adds a modest fee (or nothing, for Copilot) to software you already own, rather than a whole new platform subscription. For an individual testing the waters, SlidesAI's free plan costs nothing to find out whether the add-in workflow suits you at all — which is exactly where to start.

What about NotebookLM?

You will sometimes see NotebookLM mentioned alongside these, but it is not an add-in and not really a deck editor. It is Google's research tool: it turns your source documents into slide decks and video overviews, but its PowerPoint export is image-based, not editable. It is excellent for the research-and-summarise step, and the wrong tool if you need to edit the resulting slides. Keep it in mind for understanding a pile of documents, not for building a deck you will revise.

The honest recommendation

For most people who want AI inside the tools they already use, the decision is simple:

• Already on Microsoft 365? Try Copilot first — you may already be paying for it.
• Want the most capable add-in and you edit decks a lot? Plus AI.
• Just want a cheap or free way to turn text into slides? SlidesAI.

And the unpopular truth worth stating: if you make one deck a month, even a free add-in may be more than you need — Google Slides and PowerPoint both build perfectly good presentations on their own. Add-ins earn their keep when AI generation genuinely saves you time you would otherwise spend, week after week. Try SlidesAI's free plan first; it will tell you quickly whether the workflow is worth paying to expand.

Frequently asked questions

What is the best AI add-in for Google Slides? Plus AI is the most capable — it generates and edits decks natively in Google Slides (and PowerPoint). SlidesAI is the cheaper, simpler alternative with a free plan. Both produce native, editable Google Slides files.

Is there a free AI add-in for PowerPoint? SlidesAI has a genuine free plan (12 presentations a year) and works in PowerPoint. Plus AI is trial-only, and Microsoft Copilot requires a paid Microsoft 365 licence, so it is not free in the usual sense.

Do these add-ins export editable slides, or images? Plus AI, SlidesAI and Copilot all produce native, editable slides, because they work inside the host app rather than exporting to it. That is the main advantage of an add-in over a standalone maker. (NotebookLM, by contrast, exports image-based slides.)

Can these add-ins edit a deck I already have? Plus AI is the best at this — it inserts, remixes and rewrites individual slides in an existing deck. Copilot can restyle and add to existing PowerPoint files. SlidesAI is focused on generating new decks and is weaker at editing.

Do I need Microsoft 365 to use Copilot in PowerPoint? Yes. Copilot in PowerPoint is not sold as a standalone product; it requires a paid Microsoft 365 plan that includes Copilot access. If you are not already a Microsoft 365 user, Plus AI or SlidesAI will be easier and cheaper to adopt.

Which is better for a mixed team using both Slides and PowerPoint? Plus AI, because it is the one add-in that works fully in both. SlidesAI also supports both but with less depth. Copilot is PowerPoint-only, so it is a poor fit for a team that also lives in Google Slides.

Will my IT department need to approve an add-in? Possibly. Managed Google Workspace and Microsoft 365 environments often require an administrator to approve third-party add-ins before installation. Check with whoever runs your workspace first. Copilot avoids this, since it is a first-party Microsoft feature rather than a third-party add-in.

Are add-ins as good as standalone tools like Gamma? For design flair, no — an add-in is bounded by its host app's look, so it will not match Gamma's distinctive style. For staying in your existing workflow and producing editable, native files with no export headaches, add-ins are better. It comes down to whether you value distinctive design or a frictionless workflow.

Pricing, plans and features change often — confirm the current details on each vendor's own site before you buy.