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Form4API vs sec-api.io
Updated 2026-07-12. By Theodor Nielsen, founder of Form4API. Pricing and features checked July 2026 from sec-api.io's public pricing and docs pages.
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sec-api.io and Form4API both parse SEC Form 4 filings, but differ on three concrete points: free tier (Form4API's 500 calls/day is ongoing; sec-api.io's 100 calls is a one-time trial), real-time delivery (Form4API ships webhooks; sec-api.io offers a WebSocket stream only on its $199+/mo tier), and latency transparency (Form4API publishes a live, measured figure on /status; sec-api.io asserts a fixed "~300ms" figure for its indexing step). sec-api.io is the stronger choice for anyone whose work spans the broader SEC corpus — see when sec-api.io wins below.
Free tier math: 500/day forever vs 100 lifetime
sec-api.io's free tier is 100 API calls, total — a one-time trial, not a daily or monthly allowance. Once those 100 calls are spent, evaluating further requires a paid plan starting at $49/mo billed annually ($55/mo billed monthly).
Form4API's free tier is 500 calls a day, indefinitely, with no credit card required. For someone prototyping against real data over more than an afternoon — building a screener, testing a webhook receiver, backtesting a strategy — that's the difference between a genuine evaluation window and running out of calls on day one.
Webhooks vs WebSocket-only-at-$199
sec-api.io's real-time option is a Real-Time Filing Stream API delivered over WebSocket — and it's only available on the Business Internal Use tier, $199/mo billed annually ($239/mo monthly) and above. A WebSocket means your application maintains a persistent connection, handles reconnects after drops, and processes an ordered stream — more infrastructure than most teams want to own for what is fundamentally an alerting problem. No webhook product was found on sec-api.io at any tier.
Form4API takes the opposite shape: HMAC-signed webhooks on the paid plans, with automatic retries (roughly +2 minutes, then +16 minutes) over about 29 hours before a delivery is marked dead. You register an HTTPS endpoint once and receive a POST when something happens — no connection to keep alive, no stream to parse.
Measured latency vs an asserted number
sec-api.io states that "new insider transaction data is extracted, indexed, and made searchable within an average of 300 milliseconds after a new Form 3/4/5 filing is published." That's a specific number, but it describes their indexing step, not necessarily the full pipeline from SEC publication to your application receiving the data, and it isn't independently verified or continuously published anywhere a customer can check it.
Form4API instead publishes a rolling, live figure on its status page: the full pipeline from EDGAR's getcurrent feed being updated to the transaction appearing in the API and firing a webhook, measured over a rolling 7-day window — p50 ~59 seconds, p95 ~92 seconds as of July 2026. It's described there as "measured, not asserted," and anyone can go look at the current number, not just take a vendor's word for it.
When sec-api.io is the better choice
Honesty about where a competitor wins is the point of this page — and sec-api.io genuinely wins on breadth. Reach for it over Form4API if:
- You need more than insider data. sec-api.io covers 400+ SEC form types — 10-K/10-Q/8-K, prospectuses, Form ADV, and more — where Form4API is deliberately narrow (Form 4, Form 144, 13F-HR).
- You need enforcement or accounting-quality datasets. Its AAER (Accounting and Auditing Enforcement Releases) database and SEC Enforcement Actions/Litigation Releases datasets (10,000+ actions since 1997) have no Form4API equivalent.
- You need deep Form 4/5 history. sec-api.io's insider dataset runs 2003 to present across 11.4M transactions and 277K unique insiders — a longer window than Form4API currently surfaces.
- Your workload is research breadth, not real-time alerting. If you're querying broadly across many form types rather than reacting to new Form 4 filings as they land, the WebSocket/REST combination is a reasonable fit and the webhook gap matters less.
Side-by-side
| Dimension | Form4API | sec-api.io |
|---|---|---|
| Free tier | 500 calls/day, ongoing, no card | 100 calls total, one-time trial |
| Entry price | $49/mo (Pro) | $49/mo annual, $55/mo monthly |
| Real-time delivery | Webhooks (HMAC-signed, 5 retries over ~29h) | WebSocket stream, Business tier ($199+/mo) only — no webhooks |
| Latency claim | Measured & published live on /status — p50 ~59s / p95 ~92s (rolling 7d, July 2026) | "~300ms" asserted for indexing after publication; not a full-pipeline figure, not independently verified |
| Form coverage | Form 4 + Form 144 + 13F-HR | 400+ form types, incl. AAER & enforcement datasets |
| Form 4/5 history | 3+ years | 2003–present, 11.4M transactions, 277K insiders |
| 10b5-1 / amendment awareness | Amendment-aware (4/A supersession), 10b5-1 flags queryable | Form 3/A, 4/A, 5/A included; 10b5-1 flag not confirmed |
| MCP / AI tooling | MCP server — 27 tools + 6 prompts | Official Python/Node SDKs; no MCP server found |
Sourced from sec-api.io's public pricing and docs pages as of July 2026; verify current terms before deciding.
Frequently asked questions
Is sec-api.io free?
sec-api.io offers a free trial of 100 API calls total, not a recurring allowance — once you use those 100 calls, you need a paid plan starting at $49/mo (annual) or $55/mo (monthly) to continue. Form4API’s free tier is 500 calls/day, ongoing, with no credit card required, which is a meaningfully larger evaluation budget for someone still deciding.
Does sec-api.io have webhooks?
Not as a webhook product. sec-api.io offers a Real-Time Filing Stream API over WebSocket, available only on its Business tier ($199/mo annual, $239/mo monthly) and above. A WebSocket requires you to maintain a persistent connection and reconnect on drops, which is more integration work than a webhook that simply POSTs to an endpoint you control. Form4API includes HMAC-signed webhooks, with automatic retries, on its paid plans.
Which is faster, Form4API or sec-api.io?
sec-api.io asserts an average of "300 milliseconds" for its Insider Trading API to index and make a filing searchable after publication — but that figure describes their own indexing sub-step, not independently verified, and it's ambiguous whether the clock starts at EDGAR publication or at their own ingestion-detection time. Form4API instead publishes a rolling, live-measured full-pipeline latency (EDGAR feed to API and webhook) on its /status page — p50 ~59 seconds and p95 ~92 seconds as of a recent 7-day window (July 2026). A measured, ongoing number and a one-time marketing claim aren't directly comparable; check /status for the current figure.
When should I use sec-api.io instead of Form4API?
If your work spans far beyond insider trading — enforcement actions, AAER accounting-and-auditing releases, litigation releases, or the full 400+ form-type SEC corpus — sec-api.io covers ground Form4API doesn’t touch. Its Form 3/4/5 history back to 2003 is also deeper than Form4API’s. If insider data specifically is the priority and you want webhooks plus a transparent, measured latency figure, Form4API is the narrower, insider-focused fit.