Test every breakpoint
at once. Without 5 windows.
One window, every device side-by-side. Synchronized scrolling, clicking, and forms. Debug responsive CSS in a fraction of the time.
14-day free trial. No credit card required. From $12/mo on the annual plan.
Every device.
Every screen size.
Test your responsive designs on real device dimensions with accurate pixel ratios, user agents, and device frames.
Real Device Heights
Accounts for browser UI and OS UI - see exactly what users see on actual devices.
Accurate Device Frames
Beautiful device frames for most popular devices. Perfect for presentations and screenshots.
Always Up-to-Date
Device list updated with every release. New iPhones, Pixels, and more added within weeks.
Do it once.
See it everywhere.
Every interaction is synchronized across all devices in real-time. Test user flows without repetitive clicking.
Everything you need.
Nothing you don't.
100+ features built specifically for web development workflows.
Universal DevTools
One DevTools panel controls all devices. Debug everything from a single place.
Photo Studio Mode
Move and resize devices on a free canvas. Create stunning mockups with custom backgrounds.
Session Manager
Log in with different user accounts on different devices simultaneously. Test all user roles at once.
Project Workspaces
Save configurations per project: bookmarks, notes, presets, snippets. Switch contexts instantly.
Theme Testing
Test light and dark themes simultaneously. Switch color schemes across all devices at once.
i18n Support
Quick switch devices to any locale. Test your internationalization without leaving Sizzy.
Butler Commands
Power user command system. Convert colors, encode strings, search npm, caniuse, and more.
Screenshots & Recording
Capture screenshots on any device or all at once. Record videos or GIFs of your interactions.
Project Bookmarks
Bookmarks tied to projects, not browsers. Your development shortcuts stay where you need them.
QR Code Sharing
Scan QR code to open current URL on your phone. Automatically converts localhost to local IP.
Flexible Layouts
Horizontal, vertical, or grid layouts. Individual zoom per device. Find your perfect setup.
Recording History
Every session saved with timestamps. Search past recordings and re-test whenever needed.
...and 90+ more features
Start your free trial→Debug CSS
like never before.
Debugging responsive layouts is easier with tools built specifically for visual debugging. No more shipping debug code to production.
Screenshots that
actually look good.
Create stunning mockups for presentations, social media, and documentation. Move devices freely, choose backgrounds, and export pixel-perfect images.
Free Canvas Positioning
Drag and resize devices anywhere on the canvas
Custom Backgrounds
Gradients, solid colors, or your own images
Device Frames
Beautiful realistic frames for all devices
Export Options
PNG, JPG, or record as video/GIF
Test all user roles.
At the same time.
No more logging in and out repeatedly. Assign different user sessions to different devices and test your entire permission system in one view.
Multiple Accounts
Log in with different user accounts on different devices. Admin on desktop, user on mobile.
Permission Testing
Verify that role-based permissions work correctly. See what each user type can access.
Save as Presets
Save session configurations as presets. One click to restore your entire testing environment.
Built for how you actually work
Every feature in Sizzy was designed to solve a real problem developers face every day.
Not just a browser.
A development workspace.
Chrome and Firefox are great browsers. But they weren't built for web development. Sizzy was.
Sizzy is built on Chromium - your favorite Chrome extensions work perfectly.
Loved by 10,000+ developers
Don't take our word for it. Here's what developers around the world say about Sizzy.
If you aren't using @sizzyapp to test your web projects, you've goofed. This app saves me so much time manually resizing windows and toggling dev tool settings - plus, synchronized scrolling is straight magic
Just bought a lifetime license to @thekitze's https://sizzy.co because it seems like a MUCH better dev browser than Chrome/Brave/etc. for typical development. Especially looking forward to 'sessions' allowing me to easily be logged in as different users simultaneously
Before @sizzyapp: Damn, I forgot to test this on smaller screen sizes. *installed Sizzy* Now: Wow, looks great on all screen sizes! Let's push this to production!
As a UX/UI Designer Sizzy helps me test the designs I receive from developers and save time testing on different layouts/screen sizes. Also, I can experiment with html/css directly and get back with very specific feedback to them.
I've been using @sizzyapp for the past couple of days and damn, it feels good. Writing CSS doesn't make my blood boil anymore and testing changes in chrome feels like pounding nails with a screwdriver
I feel like @sizzyapp doesn't get enough love. It's an incredible app for web development. And only $7/mo it pays for itself many times over.
If anyone designs, tests and audits websites... @sizzyapp is just amazing... You can test a site or app across loads of devices/browsers in one click
Sizzy is a powerful selling tool. When we have a prospect who doesn't have a responsive site, when we show them their site on Sizzy, they are impressed and we look even more professional.
Secure & Up to Date
Always running the latest Electron and Chromium versions
Privacy First
No localhost URLs stored, no history storage (even locally)
Actively Maintained
Bugs squashed and new features released almost every week
Choose your plan
Start with a 14-day free trial. No credit card required.
Cancel anytime.
Monthly
Flexible billing for short bursts of work
- Cancel or pause anytime
- Billed $15 every month
- All Sizzy features unlocked
- Standard email support
- Best for short-term projects
Annual
The default for working developers
Billed $144 yearly
- 2 months free vs paying monthly
- One $144 charge per year
- All Sizzy features unlocked
- Priority email support
- Locks in current pricing on renewal
Lifetime
Pay once, own it for good
Pays for itself in under 3 years vs monthly
- One $499 payment, never billed again
- Every future Sizzy update included
- Transferable license you actually own
- Priority email support, direct line
- Immune to future price changes
All signups happen on portal.sizzy.co. Stripe-secured payments.
Start your free trial in the portal
There is no public download link anymore. Create your account on portal.sizzy.co to access Sizzy and manage everything from one place.
Create your account
Sign up on portal.sizzy.co to start your 14-day free trial.
Start with full access
Try every core Sizzy workflow first. No credit card required to get started.
Manage everything in one place
Your signup, billing, and product access all live in the portal.
14-day trial · No credit card required
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