# Similarweb (slim)

> Similarweb estimates website and app traffic from panel and other data sources. Its REST and Batch APIs and a hosted MCP server return visits, engagement, traffic channels, keywords and SERP data for a domain, under a paid subscription.

- Full: https://www.anchorterminal.com/tools/similarweb.md (~7,250 tokens) · this version ~1,780 tokens · JSON https://www.anchorterminal.com/tools/similarweb.json · canonical https://www.anchorterminal.com/tools/similarweb
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-08

**D · 46/100 · rank #566 of 629 · #5 in SEO & search visibility · not agent-ready · confidence medium**


Assessment: The V5 API returns traffic estimates, keyword clicks and SERP positions with selectable metrics, and the hosted MCP server accepts OAuth with a read scope. Access needs a Business, Enterprise or API-only subscription sold through sales, with no API trial, public price per credit or public status page found.

## Facts

- Kind: HTTP API · vendor: Similarweb Ltd. · category: SEO & search visibility · legal entity: Similarweb Ltd. · provenance 75/100
- Endpoint: `https://api.similarweb.com` (HTTP)
- Auth: OAuth or key · pricing: Paid · x402: no · licence: Proprietary service under Similarweb's terms of use
- Probe metrics: not measured yet (probes haven't run)
- APIs: REST API V5 at https://api.similarweb.com/v5/ (117 reference pages in the V5 index, covering website, search, app, company, Amazon, cross-retail and generative AI data). Batch API at https://api.similarweb.com/batch/v4/ for reports of up to 1 million domains. Rank Tracking API under /v4/rank-tracker/
- MCP server: Hosted at https://mcp.similarweb.com. `api-key` header or OAuth (authorisation code with PKCE, refresh tokens, dynamic client registration, revocation endpoint, scope `read`). Vendor guides for Claude, ChatGPT, Cursor, Microsoft Copilot and Perplexity
- SEO data: Traffic and engagement (visits, bounce rate, pages per visit, visit duration, page views, unique visitors), traffic channels, referrals, geography, website rank, website keywords (clicks, traffic share, position, top URL, intent), keywords overview (volume, CPC, difficulty), SERP players and landing pages. No backlink endpoint found
- Credentials: API keys created by account admins, up to 3 active per user, no expiry, activation toggle, credit limits per user. V5 uses one key for REST and Batch
- Rate limits: REST 10 requests a second per account. Batch 20 pending requests per user. Exceeding the monthly credit allowance also returns 429
- Errors: 401 data not found (REST) or unauthorised (Batch), 403 invalid key or no credits, 429 too many requests, 101 dates not in range, 102 granularity not supported, 103 country not available, 500 internal error (Batch). Responses carry `status`, `error_code` and `error_message` in `meta`
- Pagination: `limit` (default 100), `offset`, `sort` and `asc` on aggregated endpoints, plus `metrics`, `country`, `granularity`, `web_source`, `start_date` and `end_date`
- Data freshness: Daily data within 72 hours, monthly data by the 10th of the following month, no real-time data, per the FAQ. Each response carries `last_updated`
- Billing: Data credits, reset monthly with no rollover. 1 credit per result on most endpoints, 1 per 100 results on keyword endpoints. Price per credit is not published
- SDKs: None found. The FAQ says the API works with any HTTP client. Add-ons exist for Google Sheets, Excel and Looker Studio
- Certifications: SOC 2 Type II and ISO 27001 per https://www.similarweb.com/corp/privacy-security/
- Status: No public status page found. similarweb.statuspage.io redirects to a login

- Scores: Reliability 35, Performance pending, Schema & documentation 63, Agent ergonomics 67, Security & auth 52, Payments & pricing 5, Task success pending, Maintenance & community 33, Transparency & trust 60 · total over the 7 assessed categories
- Why: Reliability, Graded as a hosted service, on the V5 REST API and the hosted MCP server. · Schema & documentation, No public OpenAPI file found. · Agent ergonomics, V5 requests name the metrics wanted and take `limit`, so responses can be sized. · Security & auth, Revocable API keys created by admins, with up to 3 per user, no expiry and credit caps per user, plus OAuth with PKCE and a `read` scope on… · Payments & pricing, No x402, MPP or L402 found (0). · Maintenance & community, The V5 docs version shows a publish date of 24 September 2026 in the page data, and the migration guide dates the legacy endpoint deprecatio… · Transparency & trust, Closed service under public terms last updated 19 March 2025 (15 of 30).
- Sources: 26, open questions: 7, both in the full twin
- Capabilities: seo.traffic, seo.keywords, seo.serp, seo.rankings, lead.enrichment, data.company
- JSON: https://www.anchorterminal.com/api/v1/tools/similarweb.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/similarweb.svg` or a link to https://www.anchorterminal.com/tools/similarweb from a page on similarweb.com or one of its subdomains, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Send the key in the `api-key` header. The capabilities endpoint documents `?api_key=` in the URL, which puts the secret in logs
2. Stay under 10 requests a second. A 429 can also mean the monthly credit allowance is spent, so call `/capabilities` (free) before retrying
3. Pass domains in lower case without `www.` or a path. The docs list 401 as data not found for a malformed domain
4. Request only the metrics, countries and months needed. Credits multiply across domains, metrics, countries and periods, and daily granularity costs about 30 times monthly
5. Website keywords accept monthly granularity for the last three months only, and `position` isn't returned for worldwide

## Connect

```bash
curl -G "https://api.similarweb.com/v5/website-analysis/websites/traffic-and-engagement" \
  -H "api-key: $SIMILARWEB_API_KEY" \
  -d "domain=nike.com" -d "metrics=visits,bounce_rate,pages_per_visit" \
  -d "granularity=monthly" -d "start_date=2024-10-01" -d "end_date=2024-12-31"
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/similarweb

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Manifold | C | 56.2 | seo.keywords, seo.serp, seo.rankings, seo.traffic, lead.enrichment, data.company | https://www.anchorterminal.com/tools/manifold-mcp.min.md |
| DataForSEO | B | 64.9 | seo.keywords, seo.serp, seo.rankings, seo.traffic | https://www.anchorterminal.com/tools/dataforseo.min.md |
| Semrush API + MCP | D | 53.1 | seo.keywords, seo.rankings, seo.traffic, seo.serp | https://www.anchorterminal.com/tools/semrush.min.md |
| Ahrefs | D | 49.8 | seo.keywords, seo.serp, seo.rankings, seo.traffic | https://www.anchorterminal.com/tools/ahrefs.min.md |
| Moz API | E | 45.3 | seo.keywords, seo.serp, seo.rankings | https://www.anchorterminal.com/tools/moz-api.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)