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Head-to-head · Threat Modeling Software

CAIRIS vs ThreatOpus

  • Updated Oct 2026
  • Both researched from official sources
  • 5 checks side by side
Higher score CAIRIS #1 in Threat Modeling Software 9.4/10 Free plan Free plan✓ 4 of 4 features Visit CAIRIS
ThreatOpus #4 in Threat Modeling Software 9.1/10 Free plan Free plan✓ 4 of 4 features Visit ThreatOpus

CAIRIS leads on 0 checks, ThreatOpus on 0, and 5 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreCAIRIS · 9.4/10
  • Free planboth

CAIRIS scores higher on our rubric for threat modeling software: 9.4 against 9.1 out of 10; our editors rank them #1 and #4.

CAIRIS is the better fit for teams needing broad, open-source threat modeling. ThreatOpus is the better fit for teams wanting affordable workflow-integrated modeling.

  • CAIRIS fits best

    Teams needing broad, open-source threat modeling

  • ThreatOpus fits best

    Teams wanting affordable workflow-integrated modeling

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature CAIRIS 9.4/10 Visit ↗ ThreatOpus 9.1/10 Visit ↗
At a glance
Editor score 9.4 9.1
Ranking #1 in Threat Modeling Software #4 in Threat Modeling Software
Best for Teams needing broad, open-source threat modeling Teams wanting affordable workflow-integrated modeling
Pricing model Free Free plan + paid
Starting price Free plan £129.99/mo
Free plan ✓ ✓
Free trial — —
Deployment Cloud, Self-hosted Cloud, Self-hosted
Platforms Web, Windows, macOS, Linux Web
Support Docs Email, Docs
Built for Small business, Mid-market, Enterprise Small business, Mid-market, Enterprise
Features CAIRIS 4/4 · ThreatOpus 4/4
Attack-path analysis ✓ ✓
Risk prioritization ✓ ✓
Collaborative review ✓ ✓
Templates and frameworks ✓ ✓
Specs
Project limit Not checked yet Not checked yet
Modeling methods Multiple Multiple
Deployment Both Both
Our review
Pros
  • Combines data-flow, threat, requirements, and architectural modeling
  • Includes risk scoring, attack trees, patterns, and reusable templates
  • Supports self-hosting, APIs, imports, exports, and generated documentation
  • Free plan includes threat modeling, PR reviews, STRIDE, and collaboration tools
  • Imports OpenAPI and Terraform with attack-path context and mitigation tracking
  • Connects with major SCM, CI, chat, and collaboration platforms
Cons
  • Its broad scope may require more modeling coordination than focused tools
  • Self-hosted deployment places infrastructure responsibility on the organization
  • The feature set extends beyond teams seeking only basic threat diagrams
  • Free plan is limited to one repository and one SCM or CI provider
  • All listed methodologies are reserved for the Pro and Enterprise tiers
  • Single sign-on and unlimited workspaces are Enterprise features
Our verdict

CAIRIS is an open-source platform for designing, specifying, and validating secure and usable systems. It is intended for security designers, requirements engineers, researchers, educators, and organizations working on software or…

Read the review →

ThreatOpus is a cloud-hosted security platform for security, platform, and engineering teams that want threat modeling connected to development workflows. It combines AI-assisted modeling with pull-request security checks, allowing teams…

Read the review →
  1. CAIRISThreat Modeling Software 9.4Free plan
  2. ThreatOpusThreat Modeling Software 9.1Free plan

Strengths and trade-offs

  • CAIRIS — where it wins

    • Combines data-flow, threat, requirements, and architectural modeling
    • Includes risk scoring, attack trees, patterns, and reusable templates
    • Supports self-hosting, APIs, imports, exports, and generated documentation

    Where it doesn't

    • Its broad scope may require more modeling coordination than focused tools
    • Self-hosted deployment places infrastructure responsibility on the organization
    • The feature set extends beyond teams seeking only basic threat diagrams

  • ThreatOpus — where it wins

    • Free plan includes threat modeling, PR reviews, STRIDE, and collaboration tools
    • Imports OpenAPI and Terraform with attack-path context and mitigation tracking
    • Connects with major SCM, CI, chat, and collaboration platforms

    Where it doesn't

    • Free plan is limited to one repository and one SCM or CI provider
    • All listed methodologies are reserved for the Pro and Enterprise tiers
    • Single sign-on and unlimited workspaces are Enterprise features
  • CAIRIS9.4/10 · Free plan

    A broad open-source choice for teams connecting threats, requirements, architecture, and risk.

    Visit CAIRISFull verdict →
  • ThreatOpus9.1/10 · Free plan

    A workflow-integrated threat modeling platform with a capable free plan and broad CI/CD coverage.

    Visit ThreatOpusFull verdict →

More comparisons

All threat modeling software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update