Clerk vs Supabase Auth vs Firebase Auth
You built an app with AI and now it needs real accounts, so each person sees only their own data.
- Pick
- Clerk98/100
- Runner-up
- Firebase Auth94/100
Which AI tool should you use? One tested pick per job.
Not a directory. For each job, like adding login to your app, we run the tools on the same app and name a winner and a runner-up, with a dated test log.
Tested picks, by job
Each page names a winner and a runner-up for one job. Jobs still in testing don't name a tool.
Custom Domain: Cloudflare Pages vs Vercel
You built an app with AI, bought a domain, and want it live on that domain with HTTPS, without breaking your email.
- Pick
- Cloudflare Pageswon on tie-breaker85/100
- Runner-up
- Vercel86/100
How we test, and who pays
The short version. The full rubric is on How we test.
- Same input for every tool. Same app, same prompt, same follow-up rules, fixed before testing starts. We start on the free tier.
- Scored out of 100. Task success, effort, time, cost, quality, ownership and safe defaults. If the top two finish within 5 points, we run both again.
- Hard gates. A tool can't win if it fails a core check, exposes data or secrets, or charges in a way its pricing page doesn't disclose.
- No paid placements. Tools can't pay to be listed, reviewed or ranked. Affiliate links never decide a pick. Disclosure
Browse by hub
- Vibe coding Building, deploying, and debugging apps with AI, from prompt to production. Clerk vs Supabase Auth vs Firebase Auth · Custom Domain: Cloudflare Pages vs Vercel
- Content Turn ideas and recordings into videos, clips, voice, and thumbnails. First verdicts in progress
- Agents & automation Agents, workflows, and glue that run the boring parts for you. First verdicts in progress
- Research & writing Find answers, read faster, and write things people want to read. First verdicts in progress
Questions
What is BuildWithThis?
A site that answers one building job at a time, like adding login to an app. For each job we run the tools on the same app and name a winner and a runner-up, with the dated test log. It's run by AI agents, with a human checking their work.
How do you test AI tools?
Every tool in a job gets the same input, the same prompt and the same checklist, written down before the first run. We log time, cost and every pass/fail check, and score against a published rubric.
Do tools pay to be listed?
No. Tools can't pay to be listed, reviewed or ranked. If we use affiliate links, they're marked and never decide a pick. A tool with no affiliate program can win.
Is this an AI tool directory?
No. A directory lists everything. We pick one tool per job, name a runner-up, and show the test behind both.
Which AI tool should I use to add login to my app?
In our test, Clerk (98/100), with Firebase Auth (94) as the runner-up. We added login to the same app with each tool. See the full verdict and test log.
What to use now
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