Tools you can use in your browser, right now.

Quick checks, calculations, format conversions, and sandboxes for security, data, and architecture work. No setup, no sign-in for most tools.

43 browser tools43 open without sign-in
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Close-up code editor view representing browser-based technical tools
Cybersecurity19
API Security Scanner
Scan APIs for OWASP Top 10 vulnerabilities, authentication issues, security header misconfigurations, and more.
FreeRuns in browser
Certificate Viewer
Inspect X.509 PEM certificates with basic format validation and SHA-256 fingerprinting (local, in-browser).
FreeRuns in browser
Control Mapping Tool
Map security controls to compliance frameworks like NIST CSF, ISO 27001, and CIS Controls.
FreeRuns in browser
Cookie Checker & Analyser
Analyse cookie security attributes including Secure, HttpOnly, and SameSite flags. Identify security vulnerabilities and GDPR compliance issues with actionable recommendations.
FreeRuns in browser
CVE Impact Analyser
Analyse CVE information to assess real-world impact, exploitability, and remediation priority. Make informed decisions about vulnerability patching.
FreeRuns in browser
DMARC Inspector
Check DMARC and SPF configuration for a domain, with an optional DKIM selector check. Uses read only DNS queries over HTTPS.
FreeRuns in browser
DNS Lookup
Query DNS records and analyse security configuration
FreeRuns in browser
Entropy and Hashing Lab
Learn how hashing works and why tiny input changes can produce completely different outputs. Includes a simple entropy estimate and an avalanche demo.
FreeRuns in browser
Incident Post-Mortem Builder
Create structured post-incident reviews with timelines, root cause analysis, and action items.
FreeRuns in browser
Infrastructure Scanner
Analyze Terraform, CloudFormation, and Kubernetes configs for security misconfigurations and CIS benchmark violations.
FreeRuns in browser
Log Redaction at Scale
Automatically detect and redact sensitive information like emails, phone numbers, tokens, and PII from log files.
FreeRuns in browser
Password Entropy Analyzer
Analyze password strength with entropy calculations, crack time estimates for various hash algorithms, and pattern detection.
FreeRuns in browser
Password Generator
Create cryptographically secure passwords with customisable requirements. Uses your browser
FreeRuns in browser
Risk Register Builder
Create and prioritize security risks with likelihood and impact scoring, mitigations tracking, and exportable reports.
FreeRuns in browser
RSA Encryption Lab
Explore RSA public-key cryptography with small primes. See how key generation, encryption, and decryption work step-by-step in this educational demonstration.
FreeRuns in browser
Security Headers Analyser
Analyse HTTP security headers for security issues and compliance
FreeRuns in browser
Threat Model Generator
Generate comprehensive STRIDE-based threat models for your systems. Build data flow diagrams, identify threats, assess risks, and get mitigation recommendations.
FreeRuns in browser
Threat Modelling Lite
Create threat models using STRIDE methodology with assets, trust boundaries, and threat identification.
FreeRuns in browser
WHOIS Summary
Look up domain registration information including registrar, creation date, expiration, and name servers. Educational tool for understanding domain ownership.
FreeRuns in browser
Architecture12
Regex Tester
Test regular expressions with real-time matching, capture group highlighting, step-by-step explanation, and a built-in cheat sheet. Supports JavaScript, Python, and PCRE flavours.
FreeRuns in browser
API Spec Viewer
View and explore OpenAPI (Swagger) specifications. Browse endpoints, schemas, parameters, and responses in an interactive viewer.
FreeRuns in browser
Architecture Tradeoff Analysis
Systematically evaluate architectural options against constraints and criteria. Make informed decisions by comparing trade-offs across multiple dimensions.
FreeRuns in browser
Automation Studio Canvas
Model workflow orchestration, runbook flows, and execution handoffs with an automation-focused canvas.
FreeRuns in browser
Base64 Encoder/Decoder
Encode text or files to Base64, or decode Base64 back to its original form. Supports URL-safe encoding and file uploads.
FreeRuns in browser
C4 Studio Canvas
Create C4 context, container, and component architecture diagrams for system design documentation.
FreeRuns in browser
Decision Log Generator
Create structured Architecture Decision Records (ADRs) to document important technical decisions, their context, options considered, and rationale.
FreeRuns in browser
Enterprise Architecture Canvas
Build enterprise architecture models using TOGAF with capability, roadmap, and governance templates.
FreeRuns in browser
JavaScript Sandbox
Execute JavaScript code directly in your browser. Test algorithms, explore language features, and experiment with code snippets in a safe, isolated environment.
FreeRuns in browser
Logic Gates Simulator
Explore fundamental digital logic gates (AND, OR, XOR) with interactive inputs and truth tables. Perfect for learning computer architecture basics.
FreeRuns in browser
Sequence Diagram Generator
Create UML sequence diagrams for system design and documentation. Export as Mermaid or PlantUML syntax for use in your projects.
FreeRuns in browser
Technical Debt Qualifier
Assess and prioritize technical debt items based on impact, urgency, and cost to fix. Get actionable recommendations for debt management.
FreeRuns in browser

Prefer structured theory first?

Eight courses covering cybersecurity, AI, data, and architecture.

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