Write the spec once.Your team and AI build from it.
Start from an idea or your existing code,
then hand it all to your AI coding tools.Start from a one-line idea or your existing code,
and hand your PRD, user flows, and wireframes to your AI coding tools.
No credit card · 🔒 Your docs never train AI
I'll build the PRD first, then the user flow and wireframes.
Your spec is ready to hand to your AI coding tool.
A better way to plan, a faster way to work
See how the workflow changes for each role.
You can build on your live product,
with every team on one spec.
Excel, images and markdown, or plug into your AI tools and issue trackers over MCP
Trusted by users
Sounds good on paper? Hear it from teams already using it.
For any team building a product, what matters most is 'speed' and 'logical completeness.' Manyfast removes the planning bottleneck so teams can focus on what matters. For teams that want to move fast and stay structured, Manyfast keeps everyone working from the same spec, and that will be a big help.
I was leaning on AI for most of the planning, and publishing a project I barely knew didn't sit right. Manyfast turned the idea into a buildable spec, so the AI coding tool worked from the whole project, not just my last prompt. What came out held together end to end, and I could build straight from it.
During a company-wide AI transformation, non-developers often shipped without a spec, and we paid for it in maintenance. Manyfast set clear product standards, cut the churn, and got product, engineering and operations working from the same doc.
For a POC with an enterprise client, we ran the early product definition in Manyfast. Compared with past POCs, the time to define a product shrank by over 90%, and we handed the spec the client signed off on straight to our internal PMs and engineers.
Every PM should try Manyfast at least once. My team often says it feels like a genuinely well-built tool, and I'd recommend it to fellow PMs. What stood out most was how quickly it structures scattered thinking and discussion, so the whole team talks from the same doc.
The friction of starting from zero dropped sharply. Even Excel export gave me a solid skeleton. I could add the tabs I needed and tidy up right away. Defining the product and sharing it across teams became dramatically faster, and working from the same doc as design and engineering meant far less re-explaining context.
We tested it with a project that used to take two months. The AI framed the spec so well it almost felt unfair. Because we could produce proposal drafts much faster than the usual two to three weeks, we cut the time we spent preparing client kickoffs and early meetings.
Honestly, it blew me away. It narrowed the gap between idea and execution. In community workshops, even non-developers first built a buildable spec, handed it to AI tools, and shipped working prototypes in a day.
Mapping out the product before UI/UX got much easier. We skipped drawing wireframes by hand, aligned with clients sooner, and moved into design and dev faster. Easy doc sharing smoothed collaboration with clients and developers.
If you have ideas but can't picture the product, try Manyfast. Even without planning experience, you get a spec you can hand straight to AI tools, and a lot of the overwhelming, tedious work goes away.
Your questions, straight answers
The questions teams ask before they sign up.
Start free, right now
Core features are free. No credit card.
Start for free
When you need more, Pro gives you more credits and unlimited projects.
- 5,000 on signup + 3,000 daily
- AI chat with Manny, your AI PM
- Share via public link
- Export your planning docs
- Connect AI tools over MCP
- No credit card required
The productivity jump
Building the same product, with and without a spec.
Without a spec
2 monthsRework eats the schedule.
With Manyfast
1 weekSpec first, build once.
Proportions are illustrative.
Your first spec in three short videos
Short walkthroughs to watch before you start.
Your planning data, safe end to end
Protected in layers at every step, and never used for training.
Encrypted in transit
Every request between your browser and our servers is encrypted, from sign-in to save.
Encrypted at rest
Each field of your planning docs is encrypted on its own before it is ever stored.
Isolated by group
Role-based permissions keep every group's data out of reach of every other group.
No model training
Your planning data is technically blocked from ever being used to train any AI model.