Describe it. Get one pick per category, and why.
What do I use to build this?
And how much will it cost?What do you want to build?
Describe it in a sentence, like “an app that tracks the beans in my pantry”. You get what to build it with, what it runs on, and what it costs now and as it grows, with a source for every price.Describe it and press Plan. You get what to build it with, what it runs on, and what it costs now and as you grow, after the credits you qualify for.
Kong Is Ready to Pick
Describe what you're building and press Plan. Your recommended stack will appear here.
Prices read from each vendor’s own pricing page
Vercel
Supabase
Stripe
Clerk
Resend
Neon
Cloudflare
PostHog
317 services listed across 36 categories. 70 priced in full, plan by plan.
One place
for every stack decision.
See where the bill jumps before your users do.
Free tiers, plans and limits, side by side.
Already built? Find what to keep and what to change.
What you actually pay, next to what you planned.
See what real products are built on.
Recordings of the actual app. Inputs are illustrative; Billing shows an example account.
Give your AI assistant
access to Kong Reviews.
It plans the stack, prices it at your scale, and hands back package names, environment variables and docs. Your assistant writes the code.
Then keep going in the same chat. Pick up a saved project, price a change before it is built, track setup step by step, and ask why the bill went up.
Free while in preview.
Claude
ChatGPT
Cursor
VS Code
I’m building a booking app for yoga studios with sign-in, payments and email reminders. What should it run on, and what will it cost at 20,000 users?
recommend_stack, the tool your assistant calls, at today’s prices.See what real products
are built on.
Stacks read from each product’s public code.
How services are ranked
No vendor pays to be listed or ranked higher, and there are no referral links.
Every price change is public: who changed what, when and why.
See what startups build on.
One startup at a time: what it makes and the services it runs on, read from its public code and linked to their prices.
Already built?
Start from what you run.
Point it at your files, repository or website to see what to keep and what to change. Then bring in what you actually pay, next to what you estimated.
Sign-in required for billing and saved stacks.
Spend less time collecting bills
Import a CSV, upload a text-based PDF, paste an invoice or enter an amount. Recurring subscriptions add completed months automatically.
Supported OpenAI, Anthropic, Vercel, Stripe, AWS and DigitalOcean connections sync completed months nightly. Billing access depends on the provider; personal Claude API keys cannot read organization costs.
Forward receipts when they arrive
When receipt forwarding is enabled, send receipts to your private billing address and review the service, month and amount in Billing. It reads the email body, not attachments; upload PDFs separately.
Revisit decisions when things change
Save a stack or audit and enable alerts for price changes, approaching cost jumps, expiring credits and bills above estimates. Checks run daily using saved usage assumptions and require a confirmed email.
Pick what works.
Build what’s next.
Free while in preview. Create a free account to plan, no card needed.
Audit Your Stack
Already built? See what your app runs on, what it costs now and as you grow, what it's missing, and what to change.
1
What's it built on?
Reads its manifests and config files.
Reads hosting from its response headers and the scripts it loads (payments, analytics, errors). It can't see databases or back-end services, so add files too if you can.
Your AI coding app can already see the codebase. Connect Kong Reviews, then ask:
Audit this app's stack with Kong Reviews: detect what it runs on, then audit it for 10,000 users growing to 50,000.It reads the project, calls detect_stack and audit_stack, and shows the report in the chat.
2
What it runs on
3
What matters
Your audit appears here: a grade, what to change first, and what each service costs as you grow.
Build Library
What kinds of app are built with, and what they cost at three stages: MVP (about 100 users), Growth (about 10,000) and Scale (about 100,000). Every price comes from the cost engine with today's checked prices.
My Stacks
Stacks and audits you saved here or from your AI assistant. Turn on alerts to hear when prices, cost jumps or credits change one, or press Check to re-run it with today's prices.
Billing
What your services actually charged, next to what we estimated.
Vendors
Every developer service we've looked at. Those priced in full have every plan, what each includes and the cost as you grow; the rest show the free tier and lowest paid price from their pricing page.
Credits and lock-in come from the cost engine, so only services priced in full have them.
Showcase
Products startups have built, with the stack each one runs on, read from its public code. Filter by what it is and what it's built with, then see what a stack like it costs.
Use Kong Reviews from your AI assistant.
Add one address to Claude, ChatGPT, Cursor or VS Code. Your assistant can then plan the stack, price a change before it writes the code, keep setup on track and explain your bill, with the source and date behind every price.
Prices, Kept Honest by Everyone
Every change to a price, plan or limit is public. Trusted contributors' changes go live once their quote checks out; the rest are settled by votes and moderators. Read the moderation log, follow the change feed, or download the whole catalogue.
Settings
Admin
The sign-up plan, LinkedIn and Substack posts, outreach, users, pricing pages and automations.
Plan your stack for free.
Every tool, on this website and in your AI app, is free while Kong Reviews is in preview. There's nothing to buy.
Free
PreviewFor founders, product managers and AI coding agents
$0no card needed
- Stack recommendations from a PRD or a short description
- Cost now, as you grow, and in year one after startup credits
- Cost cliffs, and stay, optimise or switch comparisons
- 70 vendors priced in full, with every plan and what it includes, and more being added
- 317 developer services on Vendors, 70 priced in full and the rest with free tiers and starting prices, growing as we research more
- Audits of apps already built: what they run on, what to change
- MCP server with 34 tools for Claude, ChatGPT, Cursor and more
- Saved stacks with price re-checks (sign in with email or GitHub)
- Share links for any plan
Paid Plans
Not available yet
We may add paid plans later, for things like tracking real bills and team accounts. Nothing is for sale today.
Questions
What is Kong Reviews?
It scopes what you build next, a new product or a feature for the app you already have: which services to use (hosting, database, sign-in, email, payments, analytics and more), how to set them up, and what they will cost now, as you grow and after startup credits. Use it on this website with a free account, or from your AI assistant over MCP each time you plan a feature.
Where do the prices come from?
From each vendor's own pricing page. 70 of the 70 vendors in the cost engine were checked against their pricing pages in October 2026; any others are marked unverified. The other services on Vendors were read in October 2026 for their free tier and lowest paid price; the ones we couldn't read are marked Not Priced Yet. Both keep growing: we add vendors and services as we research them. Every answer lists its sources and the date each price was checked, and a price counts as out of date after 14 days. Check the vendor's page before you commit to anything.
Is it really free?
Yes. Every tool is free during the preview, within fair rate limits. There are no paid plans yet.
Do I need an account?
Yes, a free one, to plan or audit on this website. It also keeps your stacks and sends price alerts. Create it with your email address (we send a 6-digit code, no password) or with GitHub, which asks for no permissions beyond your public profile.
How do I use it from Claude or ChatGPT?
Open Connect AI and pick your app for the setup steps. Then ask in plain language, for example "Here's my PRD, what should I use?"
Do vendors pay to be listed or ranked higher?
No. Rankings come only from fit and cost, and there are no affiliate or referral links. See How we make money.
What happens to the PRD I paste?
It is read on our server with keyword rules to find requirements, then discarded. It is not stored and not sent to an AI provider. See Privacy.
How do I delete my data?
Sign in and go to Settings → Account → Delete account. That removes your account, your saved stacks and every sign-in straight away.
Can you add a vendor?
Yes, and we'll look at adding it.
Still have questions? Email [email protected].