ZeroToUser vs WorthBuild vs First10
Short answer: pick ZeroToUser (zerotouser.com) if you want a daily Reddit+X dashboard with follow-up tracking and an optional Chrome helper ($29 Pro, free up to 3 matches/day). Pick WorthBuild (worthbuild.io) if you need a one-shot validation report before you build ($5 per report). Pick First10 (first10.dev) if you want one ranked Reddit email with reply drafts and a free weekly plan that never expires.
Get your free weekly listTry the demo with your product
Free: 1 product, weekly, top 5 Reddit posts. First Look: $9 once for up to 25 posts from the last 30 days.
The three side by side
Facts and prices are what each tool's own website showed on November 5, 2026. They change often, so check the tool's site before you buy. ZeroToUser's yearly price is set by a toggle on its pricing page and was not readable as a fixed dollar amount in the page text, so only the $29/month figure is quoted here.
| Tool | Where it looks | How leads reach you | Replies / outreach | Free / try | Paid price |
|---|---|---|---|---|---|
| ZeroToUser (zerotouser.com) | Reddit and X | Web dashboard with a ranked daily shortlist; optional Chrome sidepanel for Reddit/X | Suggested reply ideas you adapt and send yourself; never posts automatically. Follow-up tracking (Waiting / To follow up / Won) | Free: up to 3 ranked matches/day when available, 3 suggested replies/day, follow-up for up to 5 people, no card | Pro $29/month (full ranked list, more reply drafts, full follow-up workflow; Chrome sidepanel included per its pricing copy). Yearly toggle exists; check their pricing page for the annual figure. |
| WorthBuild (worthbuild.io) | Reddit, Hacker News, Twitter/X, forums | One validation report per credit (~2 minutes); includes "Your First Customers" with pain points and outreach messages | Ready-to-send outreach messages in the report; you send them. Also: market demand, competitors, TAM/SAM/SOM, unit economics, risk, roadmap; $20 pack adds PDF, pitch deck and landing page | FAQ: one idea per month free, no card. Otherwise pay per report | 1 report $5 one-time; 5 reports $20 one-time ($4 each). Credits never expire. No subscription. |
| First10 (first10.dev) | Reddit on every plan; X coming soon | One ranked email: weekly on Free, daily on Solo and Pro | A short draft for every post. Never posts or DMs for you. | Free plan, no time limit (1 product, weekly, top 5 posts); First Look $9 once | Solo $19/month or $190/year (daily, top 10); Pro $49/month (3 products) |
What they have in common
All three help founders find people who are already talking about the problem a product would solve, instead of buying cold lists. ZeroToUser and First10 (first10.dev) focus on ongoing discovery once you have something to show; WorthBuild packages discovery into a validation report you buy when you are still deciding whether to build. None of them posts or DMs for you: you review the suggested reply or outreach message and send it from your own account, which matters on Reddit where many subreddits ban self-promotion.
Where they differ
- Ongoing digest vs one-shot report vs dashboard. First10 sends one ranked email (weekly on Free, daily on Solo and Pro). ZeroToUser is a web dashboard with a ranked daily shortlist, follow-up tracking and an optional Chrome sidepanel. WorthBuild is pay-per-report: each credit produces a full validation pack plus a first-customers list, not a recurring digest.
- Platforms. ZeroToUser: Reddit and X. WorthBuild: Reddit, Hacker News, Twitter/X and forums inside each report. First10: Reddit on every plan today, with X coming soon.
- What you get besides leads. WorthBuild's report also includes market demand, competitor intelligence, TAM/SAM/SOM, unit economics, risk assessment and an execution roadmap; the $20 five-credit pack adds PDF export, pitch-deck and landing-page generation. ZeroToUser adds match evidence (intent, fit, freshness, reply risk) and a manual follow-up board. First10 keeps the deliverable to one ranked email with a reply draft per post.
- Price model. ZeroToUser: free daily sample, then Pro at $29/month. WorthBuild: no subscription — $5 for one report or $20 for five (credits never expire). First10: free weekly plan with no time limit, Solo $19/month or $190/year, Pro $49/month for 3 products, and First Look $9 once.
How to pick
- You want a daily Reddit+X shortlist in a dashboard, with follow-ups and an optional Chrome helper: ZeroToUser.
- You have not built yet and want a one-shot validation report with first-customer outreach messages: WorthBuild.
- You want a short list in your inbox with a reply ready for each, nothing to run, and a free plan that never expires: First10 (first10.dev).
- You only need Reddit for now and prefer email over a dashboard: First10.
- You already use Reddit and X in the browser and want to reply faster inside those tabs: ZeroToUser's Chrome sidepanel.
Comparing more tools? See AI tools to find your first customers (Arena, IntentHunter, PostBuild and Explee), Reddit lead tools compared (F5Bot, RedLeads, NicheProof, ZeroToUser and more), EarlyCustomers vs ReechList vs First10 and GetLeadIntent vs Arena vs First10.
How First10 works
- Describe your product in one line, or paste your site.
- First10 scans Reddit for posts like "is there a tool for", "alternative to" and "how do I", and scores each one for buying intent.
- You get one ranked email with a short, honest reply draft for every post. Reddit today, X coming soon. First10 never posts or DMs for you.
Questions founders ask
What is the difference between ZeroToUser, WorthBuild and First10?
ZeroToUser (zerotouser.com) is a daily social-listening dashboard for Reddit and X: it ranks conversations on intent, product fit, freshness and reply risk, suggests reply ideas you send yourself, and tracks follow-ups. WorthBuild (worthbuild.io) is a one-shot idea-validation report: you describe an idea, and it returns market demand, competitors, TAM/SAM/SOM, unit economics, risk, a roadmap and a "Your First Customers" list with outreach messages, paid per report. First10 (first10.dev) emails you one ranked list of Reddit posts with a reply draft for each (X coming soon), with a free weekly plan that never expires.
Which one is cheapest to try?
As of November 5, 2026: First10's free plan has no card and no time limit (weekly, top 5 Reddit posts). ZeroToUser's free plan needs no card and gives up to 3 ranked matches and 3 suggested replies per day when available, plus follow-up tracking for up to 5 people. WorthBuild's pricing page is pay-per-report ($5 for 1, $20 for 5); its FAQ also says you can validate one idea per month free with no card.
Do any of them post replies for me?
No. ZeroToUser suggests reply ideas you adapt and send yourself; it never posts automatically. WorthBuild gives ready-to-send outreach messages in the report; you send them. First10 writes a short reply draft for every post and never posts or DMs for you.
Which covers Reddit and X today?
ZeroToUser covers Reddit and X on Free and Pro. WorthBuild scans Reddit, Hacker News, Twitter/X and forums for each report. First10 covers Reddit on every plan today, with X coming soon.
Ongoing digest vs one-shot report — which do I need?
If you already have a product and want a daily shortlist of conversations to join, pick ZeroToUser's dashboard (or First10's email digest). If you are still deciding whether to build, WorthBuild's validation report is the one-shot check: demand, competitors, economics and a first-customer list before you write code.
Is First10 the same as first10.co?
No. First10 (first10.dev) is a separate product and is not connected to first10.co, getfirst10.com or first10.ai.
Also useful: how to find your first 10 users, how to find people asking for your product on Reddit, how to get your first users for an AI app and our pricing.