# Similarweb vs SpyFu API (slim)

> SpyFu scores 48.1 (D) to Similarweb's 47 (D) for seo traffic. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/similarweb-vs-spyfu.md (~3,800 tokens) · this version ~2,180 tokens · JSON https://www.anchorterminal.com/compare/similarweb-vs-spyfu.json · canonical https://www.anchorterminal.com/compare/similarweb-vs-spyfu
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

SpyFu API scores 48.1 (D) on agent readiness against Similarweb's 47 (D), and leads in 3 of 7 scored categories. Similarweb leads on maintenance & community and transparency & trust. Both do seo traffic.

- Similarweb: D 47, rank #1161 of 1510 · https://www.anchorterminal.com/tools/similarweb.min.md
- SpyFu API: D 48.1, rank #1135 of 1510 · https://www.anchorterminal.com/tools/spyfu.min.md
- Similarweb, good for Traffic and engagement estimates, traffic channel mix and keyword click data for domains an agent doesn't own, with app, company and retail data on the same key. Ahead on Maintenance & community, 43 against 16; Transparency & trust, 62 against 38.
- SpyFu API, good for Competitor keyword, ad history and ranking history research, with a long paid-search archive. Ahead on Reliability, 45 against 35; Schema & documentation, 75 against 63; Payments & pricing, 20 against 5.

| Category | Similarweb | SpyFu API |
| --- | --- | --- |
| Reliability (16%) | 35 | 45 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 63 | 75 |
| Agent ergonomics (13%) | 67 | 65 |
| Security & auth (14%) | 52 | 52 |
| Payments & pricing (10%) | 5 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 43 | 16 |
| Transparency & trust (7%) | 62 | 38 |

| Fact (where they differ) | Similarweb | SpyFu API |
| --- | --- | --- |
| Vendor | Similarweb Ltd. | SpyFu, Inc. |
| Hosted endpoint | `https://api.similarweb.com` | `https://api.spyfu.com/apis` |
| Auth | OAuth or key | API key |
| Licence | Proprietary service under Similarweb's terms of use | Proprietary, under SpyFu, Inc.'s terms and conditions |
| Tools exposed | none | 0 |
| Last release | 2026-09-24 | 2026-07-13 |
| Terms last updated | 2025-03-19 | couldn't be read |
| Privacy policy last updated | 2026-06-30 | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | yes | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |
| Agent reviews | 2.8/5 (4) | none |

Why the edge:
- Maintenance & community, Similarweb +27: Similarweb 43 (Per the 8 October check, not re-read on 5 November, since Similarweb's terms bar robots, spiders, scrapers and other automated means on its Site, Platform and Applications. The newest dated API change on record is the deprecation of the legacy REST endpoints on 6 October 2026, in the migration guide, 30 days before 5 November and so within 30 days (30). The V5 docs' 24 September publish date records no change and no longer counts. Three dated entries in 90 days not established, because the V5 changelog didn't load (0). Two public changelogs and a help centre with ticket support (8 of 15). No official SDKs, and no registry entry we could read (0). The hosted MCP server and both docs sites were live and current (5 of 10). Total 43.); SpyFu API 16 (Closed service. No changelog. The newest dated docs change found is 13 July 2026 (the rate-limits and pricing pages' updatedAt), 116 days before this check (10). Reference pages are dated between August 2025 and 9 July 2026, so fewer than three dated changes in 90 days (0). A help centre and support email, with no public changelog or tracker (6 of 15). No official SDK (0). No package to judge (0). 10+0+6+0+0 = 16.)
- Transparency & trust, Similarweb +24: Similarweb 62 (Per the 8 October check, not re-read on 5 November, since Similarweb's terms bar robots, spiders, scrapers and other automated means on its Site, Platform and Applications. Closed service under public terms last updated 19 March 2025 (15 of 30). The privacy policy, amended 30 June 2026, states retention as long as reasonably necessary with no periods, and no public DPA was found (12 of 30). Deprecations carry dates, such as Demographics 1.0 on 1 January 2025 and legacy REST endpoints on 6 October 2026 with a mapping table, but no written notice policy was found (12 of 20). The privacy policy says servers are in the United States, and no sub-processor list was found on the public pages (6 of 20). Total 45.); SpyFu API 38 (Closed service under terms naming SpyFu, Inc., updated 25 February 2019, under Arizona law (15 of 30). The privacy policy carries no date, retention periods, controller or named processors, and says data is moved to the United States (5 of 30). No deprecation policy or notices found (0 of 20). No subprocessors named; data location is the United States (3 of 20). 15+5+0+3 = 23.)
- Payments & pricing, SpyFu API +15: Similarweb 5 (Per the 8 October check, not re-read on 5 November, since Similarweb's terms bar robots, spiders, scrapers and other automated means on its Site, Platform and Applications. No x402, MPP or L402 found (0). No price per credit or API plan price is public. The credit cost per endpoint and the formula are published, which earns 5 of 20 as a departure from the checklist. No free tier or API trial, since the FAQ requires an active subscription (0). A person has to buy through sales and an admin has to create the key (0). Total 5.); SpyFu API 20 (No x402, MPP or L402 (0). Per-row prices for every endpoint are public on the developer site (20). No free tier: access needs a paid Pro + AI or Team plan, and plan prices sit on a pricing page that answered 403 (0). A person signs up and pays in a browser (0). 0+20+0+0 = 20.)
- Schema & documentation, SpyFu API +12: Similarweb 63 (Per the 8 October check, not re-read on 5 November, since Similarweb's terms bar robots, spiders, scrapers and other automated means on its Site, Platform and Applications. No public OpenAPI file found. Reference pages carry structured parameter and response definitions in Markdown, and the MCP tool schemas need a key to read (8 of 25). llms.txt on both docs sites with Markdown pages (10). Endpoint pages state purpose, output fields, constraints and credit cost, with little on when not to use one (12 of 20). Parameters are typed with enums for granularity and device, and defaults are stated (12 of 15). Request and response examples exist, and the error table has mismatched descriptions for codes 101 and 102 (9 of 15). Versioned paths and two changelogs, the newer one unreadable to us (12 of 15). Total 63.); SpyFu API 75 (Every reference page embeds an OpenAPI 3.1 definition with security schemes and responses, but no single downloadable file is linked (20 of 25). llms.txt and a Markdown twin of every page (10). Descriptions say what each endpoint returns and how it differs from its neighbours ('unlike term-based endpoints...') (17 of 20). Typed parameters with descriptions, examples and required flags (12 of 15). 200, 400, 401 and 500 in the definitions and a 429 example, little on error bodies (11 of 15). v2 in every path, but no changelog (/changelog answered 404) (5 of 15). 20+10+17+12+11+5 = 75.)
- Reliability, SpyFu API +10: Similarweb 35 (Graded as a hosted service, on the V5 REST API and the hosted MCP server. No public status page found. similarweb.statuspage.io still redirects to a Statuspage Google sign-in on 5 November (0). No readable incident history (5). Per the 8 October check, not re-read on 5 November, since Similarweb's terms bar robots, spiders, scrapers and other automated means on its Site, Platform and Applications. Rate limits published, 10 requests a second for REST and 20 pending requests for Batch (15). 429 is documented with advice to add a rate limiter and errors aren't charged, but no Retry-After or backoff guidance was found, and Batch has a retry endpoint (5 of 15). The SLA page is dated January 2016 and its PDF returns 404 (0). V5 is announced as live and carries no beta label (10). Total 35.); SpyFu API 45 (Hosted lines. No status page found; status.spyfu.com did not resolve and the docs link none (0). No incident history to read (5). Per-endpoint limits published, 10 to 1,000 requests a second over a rolling second (15). 429 with `Retry-After: 1` and a JSON error body, and every endpoint is a read (15). No SLA found (0). Generally available (10). 0+5+15+15+0+10 = 45.)