The short answer
Signal is a free investor network from the venture firm NFX: search investors by sector and stage, connect Gmail to see who you already know, and track your intro list. Zalarma is a US-focused investor database built around fit (stage, check size, sector, state and investor type), with 33,282 US startup-investor records and a 5-investor match service.
- Signal is free, and NFX says it will never charge for it (checked 2026-11-01).
- Signal is built around a curated investor network and the contacts already in your Gmail.
- Zalarma covers 33,282 US startup-investor records, including angels, angel groups and family offices by state (Zalarma investor database, as of 2026-11-01).
- Many founders use both: Signal for network mapping, Zalarma for a fit-first regional target list.
Signal and Zalarma both exist to answer the founder's hardest early question: which investors should I talk to? They come at it differently. Signal is a free community tool run by NFX, a venture firm. It helps founders find investors by sector and stage, uncovers the investor contacts already in their Gmail, and tracks an intro list. Zalarma is an investor database for founders outside the usual circles. It helps them find the angels, angel groups, micro-VCs, family offices and regional funds that fit their stage, sector and city, and plan a warm path to each.
Signal details below come from its official FAQ and home page, checked on 2026-11-01.
At a glance
| Zalarma | Signal by NFX | |
|---|---|---|
| Who it's for | Pre-seed to Series A founders, especially outside Silicon Valley and the big accelerator circuit, who need investors that fit their round. | Founders looking for investors, and investors (VCs, scouts and angels) who want a public investing profile and a co-investor network. |
| Data coverage focus | US startup investors. 85,848 investor and firm records in total, including 33,282 US records tagged as startup investors (angels, VCs, micro-VCs, family offices, corporate VCs, accelerators), each citing its public source. (Zalarma investor database, as of 2026-11-01) | Investors, VCs, scouts and angels that Signal describes as "highly sought after by founders and vetted" by founders and other investors. Profiles show past investments, sectors and target criteria, with sector and stage rankings. |
| Pricing (as published, checked 2026-11-01) | No published price. Request access to the database, or ask for a free match list. | Free. Signal's FAQ says it is "a 100% free tool from NFX" and that NFX will never charge for it. |
| Strengths | Filters built around investor fit, including state/metro and check size. Investor profiles with focus, stages and portfolio signals. Watchlists, alerts, CSV export. A "Get matched with 5 investors" service. | Free. Connect Gmail to see which investors you already know and who could introduce you. Intro list and fundraising tracking. Investor profiles written by the investors themselves. |
| Limits | US focus. Investors only, not company or market data. No built-in deck hosting or fundraising CRM. CSV export is quota-limited; research briefs are on premium. | Coverage leans toward investors who are active in the network, so smaller regional angels and family offices may be harder to find. Network features work best if you connect your email and invite others. |
| Best for | A fit-first US target list, especially regional angels, angel groups and family offices, plus a plan for warm introductions. | Mapping your existing network to investors and tracking intros, at no cost. |
How they differ in practice
Network graph vs fit filters
Signal's core idea is the network. You connect Gmail, Signal shows which investors you already have in your contacts, and you build an intro list from the connections you and other founders share. If you already know a lot of founders and operators, that graph can surface introductions you didn't know you had.
Zalarma starts from fit instead. You filter by the things that decide a yes: stage, check size, sector, state or metro, and investor type. Then each profile shows the context that makes an introduction work, such as focus, stages, portfolio signals and the public source behind the record. That's useful when your network is thin, which is exactly the situation many founders outside the big hubs are in.
Who shows up
Signal says its profiles are for investors who are sought after by founders and vetted by others, and investors fill in their own profiles. That keeps quality high, and it means the list leans toward investors who are active in that community.
Zalarma's US coverage is wider and more local by design. Of the US startup investors in our database with a known state, 10,508 are based outside California, New York and Massachusetts, and 8,652 US records list pre-seed as a stage (Zalarma investor database, as of 2026-11-01). That includes angel investors, family offices and micro-VCs that may never appear in a national ranking.
Pricing
Signal is free, and NFX says it always will be. Zalarma doesn't publish a price; access to the database is by request, and you can ask for a free match list first. If budget is the deciding factor, start with Signal.
When to choose Signal instead
- You want a free tool and don't need anything else yet.
- Your inbox is full of founders and operators. Signal's Gmail connection can turn that network into intro paths quickly.
- You're targeting well-known seed funds and scouts who keep active profiles on the network.
- You want to see investor rankings by sector and stage as a starting point.
When Zalarma fits better
- You're raising in the US outside the big hubs and want investors by state or metro, including angel groups and family offices near you.
- Your network is thin, so you need investor context that helps you earn a warm introduction rather than one you already have.
- You want check size and investor type as filters, not only sector and stage.
- You'd rather start from 5 hand-picked investors, each with a one-line why-they-fit, delivered within 2 business days.
Using both
These tools don't cancel each other out. A practical workflow: build a fit-first list of 40 to 80 investors in Zalarma, then check which of them you can reach through people you already know using Signal's network view. Track the rest with the steps in our warm intro playbook and target list guide. For investors where no intro path exists, our cold email guide shows how to write a short, specific first message.
Bottom line
Signal is a strong, free choice when your network is your advantage. Zalarma is built for founders whose network isn't their advantage yet: it shows you which US investors fit your stage, check size, sector and city, and helps you plan a warm path to them.
Frequently asked questions
Is Signal by NFX free?
Yes. Signal's FAQ says it is a 100% free tool from NFX and that NFX will never charge for it (checked 2026-11-01).
Does Signal need access to my Gmail?
Signal asks founders to connect Gmail so it can show the investor contacts already in their inbox. It's optional, but much of the network value depends on it.
Which has more regional US investors?
Zalarma is built for regional coverage: 10,508 US startup investors with a known state are based outside California, New York and Massachusetts (Zalarma investor database, as of 2026-11-01). Signal does not publish a comparable regional count.
Can I use Signal and Zalarma together?
Yes. Many founders build a fit-first list in Zalarma and then check intro paths to those investors through their own network on Signal.
How do I get matched with investors on Zalarma?
Use the match form. We hand-pick 5 investors who fit your round, each with a one-line why-they-fit, within 2 business days.