The best source for a startup idea depends on which signal you’re actually after: what’s being built, what’s being discussed, what’s already being used, or what’s being searched. There’s no single best source, only the right source for the question you’re asking.
Most “where to find startup ideas” lists mix all four types together with no way to tell them apart. That’s a problem, because a trending GitHub repo and a rising search term mean two different things. One shows early building activity. The other shows unmet demand nobody has built for yet. Confusing them leads to chasing hype instead of evidence.
This list sorts 15 real sources into the same four signal families LumenInsight uses in its Evidence Chain: build, discuss, use and search.
Sources that show what’s being built
These sources answer one question: is anyone actually shipping something in this space right now?
- GitHub Trending surfaces repos gaining stars fastest, by day, week or language. Good for spotting a technical approach before it has a name.
- Show HN is Hacker News’s dedicated launch thread format. Founders post finished or near-finished projects here, which makes it a stronger “someone built this” signal than a pitch deck.
- Product Hunt is a daily launch board where makers post new products for upvotes and discussion. High volume, high noise, but useful for spotting recurring product categories across many small launches.
- Betalist focuses on pre-launch startups still validating before a full Product Hunt-style debut, which makes it useful for catching ideas one step earlier in the pipeline.
Sources that show what’s being discussed
These sources answer a different question: are people actively talking about a problem, whether or not a product exists yet?
- Hacker News (the front page and comment threads, not just Show HN) surfaces technical and business discussion, often with detailed, skeptical commentary that’s more useful than the headline itself.
- Reddit, specifically niche subreddits like r/SaaS, r/startups and r/SideProject, surfaces recurring complaints and feature requests in the actual words users use, which doubles as free keyword research.
- Indie Hackers’ forum and post comments show founders discussing traction, pricing and failed experiments in public, which is rarer and more candid than most startup content.
- Niche Discord and Slack communities built around a specific tool or profession surface problems before they ever reach a public forum, though they’re harder to search and require actually joining.
Sources that show what’s already being used
Discussion is cheap. Usage is not. These sources confirm people are already running something, even an unpolished one, to solve the problem.
- npm download trends show adoption of JavaScript packages over time. A rough, half-documented package with tens of thousands of weekly downloads is stronger demand evidence than a polished landing page with zero users.
- PyPI download stats do the same for the Python ecosystem, which is a good proxy for data, AI and automation tooling specifically.
- Chrome Web Store rankings and review counts reveal which browser-based utilities people install and actually keep, since uninstalled extensions stop generating reviews.
- Shopify App Store rankings show which e-commerce tooling merchants pay for, which is one of the few sources here with a direct revenue signal attached.
Sources that show what’s being searched
Search happens before a product exists. That makes it the earliest signal in the chain, and also the noisiest.
- Google Autocomplete shows real, high-frequency query patterns as people type them, including the exact phrasing they use before they know a solution exists.
- Google Trends shows whether interest in a term is rising, flat or falling over time, which helps separate a genuine trend from a one-week spike.
- People Also Ask boxes and tools like AnswerThePublic surface the specific follow-up questions people have around a topic, which double as a ready-made outline for validating and later marketing the idea.
How to use these 15 sources together
No single source above is enough on its own. A term trending on Google Autocomplete with nothing built yet on GitHub or Product Hunt might be a real open opportunity, or it might be a fad with no viable business model behind it. A repo trending on GitHub with zero Hacker News discussion and zero npm downloads is a build-only spike that hasn’t been confirmed by anything else.
The practical rule: pick one source from at least two different families before treating an idea as worth pursuing. Build plus search is a strong pairing (something is shipping into demand that’s actively being searched). Discuss plus use is another (people are complaining about a problem while already patching it together with existing tools).
For a full walkthrough of how many signals are enough and how to run the check yourself, see how to validate a startup idea with the Evidence Chain method.
In short
Fifteen sources, four families: build (GitHub Trending, Show HN, Product Hunt, Betalist), discuss (Hacker News, Reddit, Indie Hackers, niche communities), use (npm, PyPI, Chrome Web Store, Shopify App Store) and search (Google Autocomplete, Google Trends, People Also Ask).
Checking one source tells you what that one community thinks. Checking one source from at least two different families is what starts to look like evidence. LumenInsight’s Daily Report runs that cross-check automatically across all four families for every idea it surfaces.