# DataForSEO vs Similarweb

> DataForSEO scores 64.9 (B) on agent readiness against Similarweb's 46 (D), and leads in 6 of 7 scored categories. Similarweb leads on security & auth. Both do seo keywords. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb
- Markdown: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb.md (~2,100 tokens)
- Slim: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

DataForSEO scores 64.9 (B) on agent readiness against Similarweb's 46 (D), and leads in 6 of 7 scored categories. Similarweb leads on security & auth. Both do seo keywords.

- DataForSEO: grade B, 64.9/100, rank #244 of 629. Markdown https://www.anchorterminal.com/tools/dataforseo.md · JSON https://www.anchorterminal.com/api/v1/tools/dataforseo.json
- Similarweb: grade D, 46/100, rank #566 of 629. Markdown https://www.anchorterminal.com/tools/similarweb.md · JSON https://www.anchorterminal.com/api/v1/tools/similarweb.json

## Which one, for what

### DataForSEO (B)

Good for: Agents and products that need raw SEO data in bulk at a low unit price, across SERPs, keyword volumes, backlinks, ranked keywords and traffic estimates, and that can work with a task queue.

Ahead on:
- Reliability, 84 against 35
- Schema & documentation, 86 against 63
- Agent ergonomics, 84 against 67
- Payments & pricing, 40 against 5
- Maintenance & community, 82 against 33
- Transparency & trust, 74 against 60

Also in its favour:
- Runs on your own machine

Watch for: The REST API takes one account-wide login and password over HTTP Basic, with no scopes or read-only credential

### Similarweb (D)

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:
- Security & auth, 52 against 45

Also in its favour:
- No incidents deducted, where DataForSEO loses 6 points for them

Watch for: API and MCP access need a Business, Enterprise or API-only plan bought through sales. The FAQ says there's no API test without a subscription


## Score by category

| Category | Weight | DataForSEO | Similarweb | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 84 | 35 | DataForSEO +49 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 86 | 63 | DataForSEO +23 |
| Agent ergonomics | 13% (16.2 this run) | 84 | 67 | DataForSEO +17 |
| Security & auth | 14% (17.5 this run) | 45 | 52 | Similarweb +7 |
| Payments & pricing | 10% (12.5 this run) | 40 | 5 | DataForSEO +35 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 82 | 33 | DataForSEO +49 |
| Transparency & trust | 7% (8.8 this run) | 74 | 60 | DataForSEO +14 |
| Negative events | ≤15 | -6 | 0 | |
| **Total** | | **64.9 · B** | **46 · D** | |

## Facts side by side

| Fact | DataForSEO | Similarweb |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | DataForSEO OÜ | Similarweb Ltd. |
| Hosted endpoint | `https://api.dataforseo.com/v3/` | `https://api.similarweb.com` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Pay per use | Paid |
| Price for seo keywords | $0.06 per call | not published |
| x402 | no | no |
| Licence | Proprietary service under DataForSEO's terms of service. The MCP server is Apache-2.0 and the Python client is MIT | Proprietary service under Similarweb's terms of use |
| Tools exposed | 4 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-06 | 2026-09-24 |
| Terms last updated | 2026-06-12 | 2025-03-19 |
| Privacy policy last updated | 2026-07-24 | 2026-06-30 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 251 stars, 32k npm/wk, 50k PyPI/wk | none |

## Verdicts

**DataForSEO.** Per-request prices are public for every endpoint, a $1 credit and a free sandbox need no payment, and the status feed shows no incident since 15 June 2026. The REST API accepts one account-wide login and password with no scopes, and no SLA or security certification was found in the reviewed pages.

**Similarweb.** 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.

## Before you call either

### DataForSEO

1. Check `status_code` on the response and on every task. HTTP 200 is returned for most errors, and 20000 or 20100 means success
2. Append `.ai` to Live and Task GET paths to get the trimmed response. The MCP `api_request` tool does this unless `noAiMode` is true
3. Build against https://sandbox.dataforseo.com/v3/ first. It is free and returns dummy data in the production structure
4. Use the standard queue (`task_post`, then `task_get` or a `postback_url`) for bulk work. Live Google Ads endpoints allow 12 requests a minute
5. Ask the account owner to set daily cost limits and an IP whitelist, since the credentials carry the whole prepaid balance

### Similarweb

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

## Questions

### Which is better for AI agents, DataForSEO or Similarweb?

DataForSEO scores 64.9 (B) on agent readiness against Similarweb's 46 (D), and leads in 6 of 7 scored categories. Similarweb leads on security & auth.

### Do DataForSEO and Similarweb need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call DataForSEO and Similarweb without installing anything?

Yes. DataForSEO has a hosted endpoint at https://api.dataforseo.com/v3/ and Similarweb at https://api.similarweb.com.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb.json, and with the fewest tokens: https://www.anchorterminal.com/compare/dataforseo-vs-similarweb.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "dataforseo", "b": "similarweb"}`. From a terminal: `anchor compare dataforseo similarweb`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/dataforseo.json and https://www.anchorterminal.com/api/v1/tools/similarweb.json

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- [Ahrefs vs Similarweb](https://www.anchorterminal.com/compare/ahrefs-vs-similarweb.md)
- [DataForSEO vs Manifold](https://www.anchorterminal.com/compare/dataforseo-vs-manifold-mcp.md)
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- [Semrush API + MCP vs Similarweb](https://www.anchorterminal.com/compare/semrush-vs-similarweb.md)