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The short list
Polypane costs $12 a month or $108 a year after a 14-day trial, and it’s a desktop app. If you mostly check layouts, something lighter may do.
| Tool | Best for | Price | Works in |
|---|---|---|---|
| Sitepeel | Quick checks from a link | Free web tool; extension paid once | Chrome extension and web |
| Responsively App | Free desktop app | Free, open source | Mac, Windows, Linux |
| Sizzy | A full dev workspace | $15 a month, $144 a year or $499 once | Mac, Windows, Linux |
| Blisk | A ready-made device list | Free 10 minutes a day; $11.99 a month | Mac, Windows, Linux |
| Responsive Viewer | A Chrome extension | Free with ads; Pro $4.99 a month | Chrome |
1. Sitepeel
Paste a link to see the site in real device frames side by side, with a list of layout problems: content wider than the screen, tiny text, small tap targets. The Chrome extension’s Responsive viewer has 60+ devices with synced scrolling.
- No accessibility or emulation suite like Polypane’s
2. Responsively App
Responsively shows a site on many devices with mirrored clicks and scrolling. It’s free and open source, and its 2.0 beta lets AI agents drive it.
3. Sizzy
Sizzy is a developer browser with side-by-side devices, separate sessions per device, terminals and coding agents. It’s the one with a lifetime price.
4. Blisk
Blisk shows phone, tablet and desktop views side by side. The free plan stops after 10 minutes a day, and its last release was in June 2025.
5. Responsive Viewer
A Chrome extension that shows many screen sizes on one canvas, with screenshots in device mockups. About 400,000 people use it.
Which one should you pick?
Questions
Is there a free Polypane alternative?
Yes. Responsively App is free and open source. Sitepeel’s responsive checker is free in your browser, with nothing to install.
How much is Polypane?
After a 14-day trial, Individual is $12 a month or $108 a year, and Business is $16 a seat a month. Prices show in your local currency.
Polypane or Sizzy?
Polypane leads on accessibility and emulation tests. Sizzy has per-device sessions, terminals and a $499 lifetime option. See also our Polypane vs Responsively page.
