VOL. XCIV, NO. 247

★ BEST INVESTING TOOLS COMPARISON ★

Sunday, May 31, 2026

Tool Comparison · Sunday, May 31, 2026

Open Payments (CMS) vs Similarweb

Open Payments (CMS) vs Similarweb: which investing tool fits your workflow? Compare pricing, features, platforms, and verdict in seconds.

Quick verdict
Open Payments (CMS) logo

Open Payments (CMS)

openpaymentsdata.cms.gov

Best for regulatory filings monitoring, and official sources

Pricing
Free
Platforms
Web, API
VS
Similarweb logo

Similarweb

similarweb.com

Best for app & website traffic, and sheets / excel add-ins

Pricing
Free • Paid plans available
Platforms
Web, API

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Comparison snapshot

Attribute
Open Payments (CMS)
Similarweb
Starting price
Free
Free • Paid plans available
Categories covered
5
5
Web app
Yes
Yes
Mobile app
No
No
API access
Yes
Yes
Regions
North America
North America, Europe, APAC, LatAm, Middle East, Africa

Who should choose which?

Choose

Open Payments (CMS) if…

  • You need three core datasets each year: general payments, research payments, and ownership/investment interests.
  • You need web search/explorer with filtering and charts; program year downloads available from the portal.
  • You need open data api (oda) for programmatic access with filtering, querying, and aggregation (soql‑style).
  • You need publication cadence: initial annual publication on/around june 30 for the prior year, plus refresh publication after the calendar-year-end review/re-attestation cycle.

Choose

Similarweb if…

  • You need website traffic and engagement analytics, including keyword research, referral sources, and a free traffic checker tool.
  • You need api v5 beta available in rest and batch modes: rest delivers on-demand json responses, while batch handles large reports for data warehouses and historical research.
  • You need webhook support for subscribing to daily or monthly data releases, with options to manage subscriptions directly.
  • You need data exporter for no-code bulk exports, including scheduled email delivery and csv downloads.

Consider alternatives if…

  • You want broader category coverage in one tool.
  • Neither pricing tier fits your budget.
See alternatives

Side-by-side feature breakdown

AttributeOpen Payments (CMS)Similarweb
Asset types
Other
Other
Experience
BeginnerIntermediateAdvanced
BeginnerIntermediateAdvanced
Regions
North America
North AmericaEuropeAPACLatAmMiddle EastAfrica
Data freshness
End of Day
End of Day
API access
REST
REST
Export formats
CSVJSON
CSVExcelJSONPDFImage

Seen enough? Open either tool and try it now.

Pricing breakdown

Pricing details

Tool

Open Payments (CMS)

Starting price

Free tierYes
Free trial

Plans & pricing

FreeFree

Tool

Similarweb

$199/mo

Starting price

Free tierYes
Free trial

Plans & pricing

FreeFree
Starter (Web Intelligence)$199/mo
Professional (Web Intelligence)$399/mo
Team (Web Intelligence)Subscription
EnterpriseSubscription

Coverage overlap

Shared categories3

Categories where both tools offer overlapping coverage.

Open Payments (CMS) strengths2

Categories covered by Open Payments (CMS) only.

Similarweb strengths2

Categories covered by Similarweb only.

Community category leaders

Vote sentiment comparison

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Still deciding? Get hands-on with both — most plans offer a free tier or trial.

Frequently Asked Questions

What's the difference between Open Payments (CMS) and Similarweb?

Open Payments (CMS) focuses on Data APIs, APIs & SDKs, and Data Visualizations while Similarweb specializes in App & Website Traffic, Data APIs, and APIs & SDKs. They overlap in 3 categories, so choose based on your preferred workflow and pricing.

How much do Open Payments (CMS) and Similarweb cost?

Good news—both Open Payments (CMS) and Similarweb offer free plans. You can try each platform without commitment and only pay when you need premium features.

Do Open Payments (CMS) and Similarweb have APIs?

Yes, both platforms offer API access for developers and quants who want to build custom integrations or automate their workflows.

Should I choose Open Payments (CMS) or Similarweb?

Choose Open Payments (CMS) if you need Three core datasets each year: General Payments, Research Payments, and Ownership/Investment Interests., and Web search/explorer with filtering and charts; program year downloads available from the portal.. Go with Similarweb if Website traffic and engagement analytics, including keyword research, referral sources, and a free traffic checker tool., and API V5 beta available in REST and Batch modes: REST delivers on-demand JSON responses, while Batch handles large reports for data warehouses and historical research. better fits how you invest.

Can I export data from Open Payments (CMS) and Similarweb?

Both platforms let you export data to spreadsheets (CSV, and JSON). This is useful for custom analysis or record-keeping.

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Curation & Accuracy

This directory blends AI‑assisted discovery with human curation. Entries are reviewed, edited, and organized with the goal of expanding coverage and sharpening quality over time. Your feedback helps steer improvements (because no single human can capture everything all at once).

Details change. Pricing, features, and availability may be incomplete or out of date. Treat listings as a starting point and verify on the provider’s site before making decisions. If you spot an error or a gap, send a quick note and I’ll adjust.