Head to head · Seo keywords · October 2026 research run

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.

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

CategoryWeight this runDataForSEOSimilarwebEdge
Reliability16%208435DataForSEO +49
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28663DataForSEO +23
Agent ergonomics13%16.28467DataForSEO +17
Security & auth14%17.54552Similarweb +7
Payments & pricing10%12.5405DataForSEO +35
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88233DataForSEO +49
Transparency & trust7%8.87460DataForSEO +14
Negative events≤15-60
Total64.9 · B46 · D

Facts side by side

FactDataForSEOSimilarweb
KindHTTP APIHTTP API
VendorDataForSEO OÜSimilarweb Ltd.
Hosted endpointhttps://api.dataforseo.com/v3/https://api.similarweb.com
TransportsHTTP, Streamable HTTP, stdioHTTP
AuthOAuth or keyOAuth or key
PricingPay per usePaid
Price for seo keywords$0.06 per callnot published
x402nono
LicenceProprietary service under DataForSEO's terms of service. The MCP server is Apache-2.0 and the Python client is MITProprietary service under Similarweb's terms of use
Tools exposed4none
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-062026-09-24
Terms last updated2026-06-122025-03-19
Privacy policy last updated2026-07-242026-06-30
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity251 stars, 32k npm/wk, 50k PyPI/wknone

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.

Other comparisons with DataForSEO or Similarweb

Machine-readable

For companies

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