Aviationstack is a scalable REST API for real-time flight tracking, historical flight data, airport info, and global aviation data.
from $49.99/mo
About Sizzy
What is Sizzy?
Sizzy is a specialized browser for web developers that lets you test responsive designs on multiple device dimensions at once — all in one window. Instead of opening five browser windows, Sizzy syncs scrolling, clicking, and form inputs across real device frames (iPhone, Pixel, iPad, MacBook, etc.) so you can debug CSS and user flows in a fraction of the time.
Who is it for?
Sizzy is built for front-end web developers, UI engineers, and designers who ship responsive websites or web apps. It’s ideal for teams that need to validate layouts across iPhones, Android phones, tablets, and desktops simultaneously. If you manage multiple screen sizes or device-specific behavior (e.g., device pixel ratios, user agents, browser chrome), Sizzy saves hours of manual testing.
Who is it NOT for?
Sizzy is not a replacement for real-device lab testing or native app debugging. It is a development tool, not a production monitoring or automation testing platform. Developers who only work on single-screen desktop layouts may find it overkill.
Real-world use cases
Common workflows include: debugging responsive CSS across iPhone and iPad models with accurate device frames; testing user flows (sign-up, checkout) by syncing clicks and forms; capturing screenshots or GIFs for bug reports and presentations; managing multiple user sessions (e.g., admin vs. regular) with Session Manager; and using Universal DevTools to inspect all devices from one panel.
Key features
- Synchronized scrolling, clicking, and forms — Interact once, see changes on every device in real time.
- Real device dimensions & frames — Accurate pixel ratios, user agents, and device frames for iPhone 15 Pro, Pixel 8, iPad Pro, MacBook Pro, and more.
- Universal DevTools — One DevTools panel controls all devices for centralized debugging.
- Session Manager — Log in with different user accounts on different devices at the same time.
- Theme & i18n testing — Toggle light/dark mode and switch locales across all devices instantly.
- Screenshots & recording — Capture screenshots or record videos/GIFs from any device or all at once.
- Project Workspaces & Butler Commands — Save project-specific settings, bookmarks, and access power-user commands like color conversion and npm search.
SaaSpartout Score
7.4
/10
Editorial score from our review methodology — not user ratings.
◆ AI advisor — 30 seconds, no signup
Why are you looking at Testing tools today?
Sizzy Pricing
Sizzy pricing: from $12/mo.
For comparison: the median starting price in Developer Tools is $19.99/month, measured across 301 tools we track. See the full SaaS Pricing Index →
Annual Plan
$12 per month, billed annually. Includes all features (synchronized scrolling, universal DevTools, session manager, screenshots, and more). 14-day free trial — no credit card required.
No monthly-only plan is publicly listed. Contact Sizzy for team or enterprise pricing.
Frequently asked questions
Is Sizzy free?
Sizzy offers a 14-day free trial with no credit card required. After the trial, the only listed plan is $12/mo (billed annually).
How much does Sizzy cost?
Sizzy costs from $12 per month on the annual plan. There is no monthly-only plan currently advertised.
What is Sizzy used for?
Sizzy is a browser for web developers to test responsive designs across multiple devices side-by-side, with synchronized clicks, forms, and scrolling.
Who is Sizzy best for?
Front-end developers and UI designers who need to quickly debug responsive CSS and flows across iPhones, Androids, tablets, and desktops.
What are the top alternatives to Sizzy?
Alternatives include Responsively App (free, open-source), BrowserStack (real device cloud), and Chrome DevTools device emulation. Sizzy is best for simultaneous, synchronized testing on one machine.
Does Sizzy have a free plan?
No free plan, but a 14-day free trial is available without a credit card. After trial, you must subscribe to the annual plan.
