How to actually compare AI PRD tools

The threads keep coming. One PM uses Perplexity, ChatPRD, Reforge, and Claude Projects and still can't find the one tool that does it all from concept to sign-off to dev. Another is skeptical of ChatPRD specifically and asks how it differs from any advanced LLM — and whether it handles technical requirements for something like an SAP implementation, where their real challenges live. A third just wants to know if a dedicated tool beats the raw model at all.

These are the right questions and they deserve a framework instead of a leaderboard, because "which is best" depends entirely on what you're comparing on — and most comparisons compare the wrong thing.

The wrong axis: output quality on a blank prompt

Give ChatPRD, Reforge, and raw Claude the same thin prompt and you'll get three competent, structurally similar documents. On this axis the tools look interchangeable, which is why the skeptic's instinct — "how is this different from a good prompt?" — feels right. On a blank prompt, it mostly isn't. The model underneath is doing the work, and a dedicated wrapper that just adds a system prompt is selling you a prompt you could write yourself.

The right axes: grounding and connection

What actually separates tools is everything around the generation:

• Does it ground the spec in your real material? Can it take your transcripts, tickets, product, or codebase and build from those — or does it only operate on what you type into a box? This is the difference between a real spec and slop, and it's where most tools are thin.
• Does it connect to the rest of the workflow? The PM who wanted "concept to sign-off to dev" was asking the real question. A tool that produces a great isolated PRD and then dead-ends — no flow, no gap check, no path to tickets — has automated one stage and left every handoff intact.
• Does it handle the technical depth you need? The SAP-implementation PM is right that a tool which only does product PRDs won't help where their pain is. Match the tool's depth to your actual work, not the demo.
• Does it keep a human gate? A tool that writes confidently and commits automatically is faster and more dangerous than one that proposes and waits.

The honest takeaway

If you're comparing AI PRD tools on how good the document looks from a one-line prompt, they'll all look fine and you'll buy on price or vibes. Compare them on whether they ground the spec in your real context and connect it to the workflow on either side, and most of the field thins out fast — because that's the hard part, and the hard part is where the actual difference is.