Polypane. For devs who care
@polypane.app
The missing half of your development environment. Chromium-based workspace for building great websites. Built for web developers who care | Try out for free at https://polypane.app | By @kilianvalkhof.com
Pinned
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
live now!
Playing around with something I barely understand: displacement filters in SVG! The backdrop in the @polypane.app header now has defraction and chromatic abberation, an upgrade from the simple blur + saturate it had.
Chromium only, with the previous style as fallback for other browsers.
Chromium only, with the previous style as fallback for other browsers.
September 9, 2026 at 8:58 AM
live now!
Reposted by Polypane. For devs who care
Pssst 🤫
We're working on an infinite canvas. What do you think?
We're working on an infinite canvas. What do you think?
September 4, 2026 at 7:12 AM
Pssst 🤫
We're working on an infinite canvas. What do you think?
We're working on an infinite canvas. What do you think?
Pssst 🤫
We're working on an infinite canvas. What do you think?
We're working on an infinite canvas. What do you think?
September 4, 2026 at 7:12 AM
Pssst 🤫
We're working on an infinite canvas. What do you think?
We're working on an infinite canvas. What do you think?
Reposted by Polypane. For devs who care
Polypane gives you more feedback and suggestions than any other tool because all those details matter.
And soon, it will show you one less.
And soon, it will show you one less.
September 2, 2026 at 4:46 PM
Polypane gives you more feedback and suggestions than any other tool because all those details matter.
And soon, it will show you one less.
And soon, it will show you one less.
Polypane gives you more feedback and suggestions than any other tool because all those details matter.
And soon, it will show you one less.
And soon, it will show you one less.
September 2, 2026 at 4:46 PM
Polypane gives you more feedback and suggestions than any other tool because all those details matter.
And soon, it will show you one less.
And soon, it will show you one less.
Reposted by Polypane. For devs who care
Our source panel can now toggle between the rendered and the server-sent HTML!
Both are automatically formatted, both are validated.
If you're not sure if an HTML issue starts on the server or in your JS, that's now super easy to find.
Both are automatically formatted, both are validated.
If you're not sure if an HTML issue starts on the server or in your JS, that's now super easy to find.
August 28, 2026 at 11:42 AM
Our source panel can now toggle between the rendered and the server-sent HTML!
Both are automatically formatted, both are validated.
If you're not sure if an HTML issue starts on the server or in your JS, that's now super easy to find.
Both are automatically formatted, both are validated.
If you're not sure if an HTML issue starts on the server or in your JS, that's now super easy to find.
if you missed it last friday, we have a new version out! 🥳
Polypane 30.1 is here!
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Polypane 30.1: Selector specificity insights, server HTML validation, and more | Polypane
Polypane 30.1 adds selector specificity highlighting to the elements panel, a new server-sent HTML view in the sources panel, passkey support in Linux and a…
polypane.app
August 31, 2026 at 3:20 PM
if you missed it last friday, we have a new version out! 🥳
Reposted by Polypane. For devs who care
Our elements panel got an exciting addition. Hover over the specificity of a selector to see each part of it highlighted, so you know exactly what's responsible.
Intelligent enough to drill down into nested `:is()` selectors, intelligent enough to drill up into nested selectors.
Intelligent enough to drill down into nested `:is()` selectors, intelligent enough to drill up into nested selectors.
August 28, 2026 at 11:42 AM
Our elements panel got an exciting addition. Hover over the specificity of a selector to see each part of it highlighted, so you know exactly what's responsible.
Intelligent enough to drill down into nested `:is()` selectors, intelligent enough to drill up into nested selectors.
Intelligent enough to drill down into nested `:is()` selectors, intelligent enough to drill up into nested selectors.
Polypane 30.1 is here!
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Polypane 30.1: Selector specificity insights, server HTML validation, and more | Polypane
Polypane 30.1 adds selector specificity highlighting to the elements panel, a new server-sent HTML view in the sources panel, passkey support in Linux and a…
polypane.app
August 28, 2026 at 11:42 AM
Polypane 30.1 is here!
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Yep, already.
We landed a few features that were so cool we just couldn't wait.
This one's not as massive as Polypane 30, so find the highlights below!
polypane.app/blog/polypan...
Reposted by Polypane. For devs who care
Well this is just cool!
It even has the invisible cone between an item and its submenu so it doesn't close as you move diagonally.
Video made in @polypane.app BTW :)
It even has the invisible cone between an item and its submenu so it doesn't close as you move diagonally.
Video made in @polypane.app BTW :)
August 28, 2026 at 9:13 AM
Well this is just cool!
It even has the invisible cone between an item and its submenu so it doesn't close as you move diagonally.
Video made in @polypane.app BTW :)
It even has the invisible cone between an item and its submenu so it doesn't close as you move diagonally.
Video made in @polypane.app BTW :)
Reposted by Polypane. For devs who care
Get an early look by checking out the demos in this article in @polypane.app which already has support for random()
polypane.app/blog/experim...
polypane.app/blog/experim...
August 28, 2026 at 5:25 AM
Get an early look by checking out the demos in this article in @polypane.app which already has support for random()
polypane.app/blog/experim...
polypane.app/blog/experim...
Reposted by Polypane. For devs who care
We've given our online CSS selector specificity calculator some nice upgrades!
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
August 26, 2026 at 11:00 AM
We've given our online CSS selector specificity calculator some nice upgrades!
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
We've given our online CSS selector specificity calculator some nice upgrades!
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
August 26, 2026 at 11:00 AM
We've given our online CSS selector specificity calculator some nice upgrades!
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
- Improved resolution of function nested specificity
- Highlighting parts while you type (using OpagueRange + Highlight API)
- Explore your selector by hovering over each part
Check it out: polypane.app/css-specific...
Reposted by Polypane. For devs who care
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
August 19, 2026 at 1:18 PM
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Check out our newest testimonial by @pointc.bsky.social 🤩
See all our latest testimonials here: polypane.app/testimonials/
See all our latest testimonials here: polypane.app/testimonials/
![Shout-out to Polypane. I've been working on a website with a fairly complex layout and I can't image [sic] developing anything without it.
Too many features to list. Just try it. You'll love it.
Craig Roblewsky
Cofounder Sleepy Dog Media Group](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:jdsp2lt772dbud7vxpoup63g/bafkreia2gwybqepaz5gjyrbu2yvszwefmtf3qmpvqzwogg4oyiwe37faom)
August 20, 2026 at 1:10 PM
Check out our newest testimonial by @pointc.bsky.social 🤩
See all our latest testimonials here: polypane.app/testimonials/
See all our latest testimonials here: polypane.app/testimonials/
Reposted by Polypane. For devs who care
Woah. Huge Polypane update.
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
August 19, 2026 at 1:24 PM
Woah. Huge Polypane update.
Reposted by Polypane. For devs who care
The best browser for developers is made by @kilianvalkhof.com.
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
August 19, 2026 at 1:43 PM
The best browser for developers is made by @kilianvalkhof.com.
Reposted by Polypane. For devs who care
Polypane v30 ✨
Network panel got more stable and insightful — see requests alone or grouped by origins, both very useful depending on your optimization angle.
Emulating svh overlay is now on by default — always see what’s ACTUALLY above the fold on mobile.
Fast startup 💨
Check out the changelog.
Network panel got more stable and insightful — see requests alone or grouped by origins, both very useful depending on your optimization angle.
Emulating svh overlay is now on by default — always see what’s ACTUALLY above the fold on mobile.
Fast startup 💨
Check out the changelog.
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
August 19, 2026 at 8:35 PM
Polypane v30 ✨
Network panel got more stable and insightful — see requests alone or grouped by origins, both very useful depending on your optimization angle.
Emulating svh overlay is now on by default — always see what’s ACTUALLY above the fold on mobile.
Fast startup 💨
Check out the changelog.
Network panel got more stable and insightful — see requests alone or grouped by origins, both very useful depending on your optimization angle.
Emulating svh overlay is now on by default — always see what’s ACTUALLY above the fold on mobile.
Fast startup 💨
Check out the changelog.
Reposted by Polypane. For devs who care
Anything random is a joy to test in @polypane.app by the way, because you really get a feel for how it behaves.
August 20, 2026 at 8:11 AM
Anything random is a joy to test in @polypane.app by the way, because you really get a feel for how it behaves.
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152 | Polypane
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major…
polypane.app
August 19, 2026 at 1:18 PM
Polypane 30 is out! 🤩
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
🛝 Playgrounds: go from .html to multi-device testing in 3 clicks
🔤 text-scale emulation
📹 recording w/ sound
🌐 Network panel filtering & sorting
✨ Sidepanel browser extensions
🔗 Standard.site validation & previews
🌍 Chromium 152
⛰️ MORE STILL
polypane.app/blog/polypan...
Reposted by Polypane. For devs who care
Cheatsheets for Flex, Grid, Anchor Positioning and Invoker Commands, by @polypane.app:
https://polypane.app/blog/cheatsheets-for-flex-grid-anchor-positioning-and-invoker-commands/?ref=frontenddogma.com
#cheatsheets #css #flexbox #grids #layout
https://polypane.app/blog/cheatsheets-for-flex-grid-anchor-positioning-and-invoker-commands/?ref=frontenddogma.com
#cheatsheets #css #flexbox #grids #layout
Cheatsheets for flex, grid, anchor positioning and invoker commands | Polypane
For CSS Day this year we created a set of cheatsheets explaining Flexbox, Grid, Anchor positioning and Invoker commands. They came out beautifully and a lot of…
polypane.app
August 15, 2026 at 8:30 AM
Cheatsheets for Flex, Grid, Anchor Positioning and Invoker Commands, by @polypane.app:
https://polypane.app/blog/cheatsheets-for-flex-grid-anchor-positioning-and-invoker-commands/?ref=frontenddogma.com
#cheatsheets #css #flexbox #grids #layout
https://polypane.app/blog/cheatsheets-for-flex-grid-anchor-positioning-and-invoker-commands/?ref=frontenddogma.com
#cheatsheets #css #flexbox #grids #layout
😍
Just a random shout-out to @polypane.app. I've been working on a website with a fairly complex layout and I can't image developing anything without it. Too many features to list. Just try it. You'll love it.
Polypane. The browser for developers who care.
Polypane has everything a browser has, plus all the tools you need to build responsive, fast, accessible, and SEO-friendly websites and apps, with multi-viewport synchronised previews and accessibilit...
polypane.app
August 12, 2026 at 7:27 AM
😍
Reposted by Polypane. For devs who care
@handle.invalid says @polypane.app is useful for accessibility nerds, so it must be true:
www.200ok.nl/tips/polypan...
www.200ok.nl/tips/polypan...
Polypane and WCAG - 200 OK - Jules Ernst
Jules Ernst, onafhankelijk webadviseur
www.200ok.nl
August 7, 2026 at 1:27 PM
@handle.invalid says @polypane.app is useful for accessibility nerds, so it must be true:
www.200ok.nl/tips/polypan...
www.200ok.nl/tips/polypan...
Reposted by Polypane. For devs who care
Cheatsheets for flex, grid, anchor positioning and invoker commands. Kilian Valkhof shares four CSS references he made after forgetting anchor positioning and grid-area syntax. Free as PDF and PNG in print-ready A5. #css #learn
polypane.app/blog/ch...
polypane.app/blog/ch...
July 31, 2026 at 10:00 AM
Cheatsheets for flex, grid, anchor positioning and invoker commands. Kilian Valkhof shares four CSS references he made after forgetting anchor positioning and grid-area syntax. Free as PDF and PNG in print-ready A5. #css #learn
polypane.app/blog/ch...
polypane.app/blog/ch...
Remember these?
Well, we made them available online using some fun CSS transitions, and we made them available as free print-ready downloads too! Go play with them here:
polypane.app/cheatsheets/
Well, we made them available online using some fun CSS transitions, and we made them available as free print-ready downloads too! Go play with them here:
polypane.app/cheatsheets/
July 27, 2026 at 1:04 PM
Remember these?
Well, we made them available online using some fun CSS transitions, and we made them available as free print-ready downloads too! Go play with them here:
polypane.app/cheatsheets/
Well, we made them available online using some fun CSS transitions, and we made them available as free print-ready downloads too! Go play with them here:
polypane.app/cheatsheets/