ChatGPT
The versatile everyday workhorse — drafting specs, quick analysis, and voice-driven interview note capture.
- Pricing
- Free (with ads); Go $8/mo; Plus $20/mo; Pro $100–$200/mo; Business from $25/user/mo
- Last verified
- 2026-07-06
What it is
OpenAI’s ChatGPT is the most widely used AI assistant, and for PMs its breadth is the point: custom GPTs for a reusable PRD-writer, voice mode for talking through a problem on a walk, image and file handling, and a huge plugin/tool ecosystem. Most PMs already have access, which makes it the lowest-friction place to start.
Our verdict
An excellent generalist and, for many PMs, the tool they’ll actually open because it’s already in their workflow. Custom GPTs are the standout for PM work — build a “PRD Writer” once with your template and tone baked in, and share it with the team. Voice mode is genuinely useful for thinking out loud before you write.
Where it falls short: on very long documents we found it more likely than Claude to drift from the requested structure and to over-confidently fill gaps, so you babysit long PRDs more. The plan matrix is confusing — seven tiers, and the cheap ones now carry ads. Team features that matter (shared workspace, admin) start at Business, which needs a minimum of two seats.
Get value in 10 minutes
- Go to Explore GPTs → Create and make a GPT named “PRD Writer.” In the instructions, paste your PRD template and add: “Always end with an Open Questions section. Flag assumptions inline. Never invent success metrics — ask instead.”
- Save it, then start a chat with your GPT and describe the feature in a few sentences.
- Iterate by section (“tighten the acceptance criteria,” “add non-goals”) rather than regenerating the whole doc — it holds structure better that way.