Intercept. Modify. Ship better web apps with Twist.
Twist is a purpose-built browser that lets you inspect and change HTTP/S requests and responses in real time—perfect for developers, product teams, and authorized security validation.
Everything you need to bend the web—safely
Powerful, reversible changes for debugging, demos, and authorized testing.
Live Request/Response Editing
Rewrite URLs, headers, payloads, and response bodies on the fly—no server redeploys required.
Rules & Conditions
Set up domain/path matching, header conditions, delays, and failure simulations to reproduce tricky bugs.
Mock APIs
Stub endpoints and design UI flows before the backend is ready. Share presets with your team.
Network Conditions
Throttle bandwidth, inject latency, and simulate offline to harden UX resilience.
Header/CSP Sandbox
Experiment with security headers and CSP policies safely without touching production configs.
Session Recording
Capture sessions and export diffs for bug reports and reproducible demos.
Squash bugs without redeploys
Tweak requests and responses locally, test migrations, and validate edge cases instantly.
- Patch responses to unblock UI work
- Force error states and retries
- Swap feature flags and config on the fly
- Share rule presets across projects
Prototype without recoding
Craft demos by mixing live pages with mocked data and alternate copy—no engineering cycles required.
- Swap copy, assets, and colors for demos
- Mock yet-to-be-built endpoints
- Save and re-run demo scenarios
- Share read-only presets with stakeholders
Validate front-end defenses
Evaluate header policies, content restrictions, and UI behaviors under altered client-side conditions on assets you are authorized to test.
- Experiment with CSP and security headers
- Assess client-side behavior under constraints
- Export reproducible test cases
Use Twist only on systems you own or have explicit permission to test.
How it works
Three steps to full-control, reversible web experimentation.
Browse in Twist
Open your site in Twist and watch requests stream into the inspector.
Create rules
Match on URLs/headers and rewrite responses, simulate delays, or stub APIs.
Share & repeat
Save presets for teammates and reproduce issues reliably.
Get Twist
Start debugging, prototyping, and testing with total flexibility.