Short answer: for client-ready consulting decks, choose Whyston. ChatGPT for PowerPoint creates editable slides, and OpenAI's own help page says to "review claims, numbers, citations where available, and slide changes before sharing or relying on them." Whyston is built so that review is fast: every number is labelled documented, derived or an assumption, and every assumption is listed.
Disclosure: Whyston publishes this page. Facts about ChatGPT come from ChatGPT's own website and documentation (linked below), reviewed in October 2026.
Side by side
| Whyston | ChatGPT | |
|---|---|---|
| Built for | Consulting-grade decks you can defend | A general assistant with a PowerPoint sidebar |
| Storyline | Governing thought, SCQA arc and MECE pillars written before any slide | No consulting structure described |
| Slide titles | An action title on every slide | Not described |
| Numbers | Every number labelled as documented, derived or an assumption; source line on each slide; Figures and Assumptions page | OpenAI advises reviewing claims, numbers and citations before sharing |
| Your sources | PDF, PPTX, DOCX, XLSX, CSV and Markdown become a citable evidence base | Files you share in the chat |
| Consulting charts | Native waterfalls, Gantt roadmaps, funnels, market-size rings, with growth arrows and callouts | Consulting chart types not described |
| PowerPoint | Native, editable PPTX; full web editor (every shape and text editable, one-click smart layouts); PowerPoint add-in on Microsoft AppSource | Editable slides inside PowerPoint |
| Price | Free (3 decks); Pro €29/month or €288/year for 20 decks a month | Included in ChatGPT plans, from Free |
Where Whyston pulls ahead
- Built for client-ready work. OpenAI asks you to review claims and numbers yourself; Whyston labels every number and lists every assumption so the check takes minutes.
- The argument first. SCQA storyline, MECE pillars and an action title on every slide.
- Consulting exhibits. Native waterfalls, Gantt roadmaps and annotated charts.
- A full slide editor. Move, resize and restyle every shape, text box and chart; smart layouts change a slide's look and feel in one click.
- A whole deck from your data room, not slide-by-slide prompting.
When ChatGPT may be enough
- A quick internal draft, when you will check every number by hand anyway.
- Editing a few slides in an existing deck.
Choose Whyston if
- The deck comes from a data room, a financial model, research or interview notes.
- A partner, a board or an investment committee will ask where each number came from.
- You need the storyline and the action titles written, not only the slides.
- The team will keep working in PowerPoint after the first draft.
See all 25 tools compared: the best AI tools for consulting decks.