--- title: Polypane 31: Canvas layout, elements panel improvements... description: Polypane 31 introduces a new infinite canvas layout for freely arranging and resizing panes, plus device presets for the latest iPhone models and a 5K screen.... canonical: https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Polypane 31: Canvas layout, elements panel improvements and Chromium 155 | daily.dev og:description: Polypane 31 introduces a new infinite canvas layout for freely arranging and resizing panes, plus device presets for the latest iPhone models and a 5K screen.... og:url: https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef og:image: https://api.daily.dev/og/posts/i9JSsC2eF.png og:image:alt: Polypane 31: Canvas layout, elements panel improvements and Chromium 155 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Polypane 31: Canvas layout, elements panel improvements and Chromium 155 **[Polypane](https://daily.dev/sources/polypane)** · 15 min read · 4 upvotes · 0 comments ## Summary Polypane 31 introduces a new infinite canvas layout for freely arranging and resizing panes, plus device presets for the latest iPhone models and a 5K screen. The elements panel gains a flex item visualisation, custom property navigation, DOM search, and style filtering. Screenshotting is more reliable with a new Visible Workspace option and better high-DPI support. Video recording now uses Mediabunny instead of ffmpeg and captures the native cursor. Other updates include per-pane zoom for accessibility testing, a 25% smaller download size, meta panel llms.txt display, smarter link checking in the outline panel, and numerous quality-of-life fixes. The release runs on Chromium 155. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What's new in Polypane 31's elements panel for debugging flex layouts? Polypane 31 adds a flex item visualisation showing how flex and sizing properties determine an element's final size. It displays base size in blue, flexibility (grow/shrink) in purple, and constraints in orange, with a black outline for actual size and a lock icon for matched constraints, plus a breakdown of final size, base size, flexibility, and constraints. _Debugging flex sizing issues gets easier with tooling like this tracked on daily.dev._ ### What Chromium version does Polypane 31 use and why does it matter for testing new CSS features? Polypane 31 runs on Chromium 155, which enables testing of newer experimental web platform features such as the CSS random() function before official release. Experimental web platform features ship enabled by default in Polypane, though they can cause pane instability, prompting a new crash overlay with reload or disable options. _Developers tracking browser engine updates for cross-browser testing follow releases like this on daily.dev._ ### How did Polypane speed up its video recording and processing? Polypane 31 replaced ffmpeg with the Mediabunny library for video processing, making most recorded videos load instantly in the video editor. It also switched to capturing the native mouse cursor directly instead of using a synthetic cursor. Mediabunny 1.60.0 fixed VP9 codec issues on Linux that previously required keeping ffmpeg for cross-platform support. _Anyone comparing video processing libraries for tooling can follow developments like this on daily.dev._ ## Similar posts on daily.dev - [Polypane 30: Playgrounds, Side Panel extension API, updated video recording and Chromium 152](https://daily.dev/posts/polypane-30-playgrounds-side-panel-extension-api-updated-video-recording-and-chromium-152-cuj2wsicc) · Polypane · 2 upvotes · 1 comments --- Tags: [#css](https://daily.dev/tags/css), [#accessibility](https://daily.dev/tags/accessibility), [#chromium](https://daily.dev/tags/chromium), [#polypane](https://daily.dev/tags/polypane) [View this post on daily.dev](https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Polypane 31: Canvas layout, elements panel improvements and Chromium 155","url":"https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef"},"datePublished":"2026-09-29T12:47:32.011Z","dateModified":"2026-09-29T12:48:00.596Z","description":"Polypane 31 introduces a new infinite canvas layout for freely arranging and resizing panes, plus device presets for the latest iPhone models and a 5K screen....","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/bc4ac9d20758bb3452336f4f19b29fbf?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/bc4ac9d20758bb3452336f4f19b29fbf?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Polypane","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Polypane","logo":"https://media.daily.dev/image/upload/s--KIZm_n0x--/f_auto,q_auto/v1782646521/logos/polypane?_a=BAMAMicg0","url":"https://daily.dev/sources/polypane"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":4},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"css,accessibility,chromium,polypane","timeRequired":"PT15M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Polypane","item":"https://daily.dev/sources/polypane"},{"@type":"ListItem","position":3,"name":"Polypane 31: Canvas layout, elements panel improvements and Chromium 155"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/polypane-31-canvas-layout-elements-panel-improvements-and-chromium-155-i9jssc2ef#faq","mainEntity":[{"@type":"Question","name":"What's new in Polypane 31's elements panel for debugging flex layouts?","acceptedAnswer":{"@type":"Answer","text":"Polypane 31 adds a flex item visualisation showing how flex and sizing properties determine an element's final size. 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