sitespeedio/sitespeed.io v40.0.0

on GitHub

Highlights

A big release. The HTML report has been almost entirely re-skinned around a unified card-based design language; Browsertime jumps to 27 with a much improved scripting API and iOS-device testing; coach-core jumps to 9 with a severity tier on every rule, an INP rule, and a set of modern-image rules.

• A new look and feel for every page of the report. Every tab and every top-level result page has been refreshed. Charts that used to need Chartist are now inline SVG with no JS dependency #4619, #4654.
• Coach severity is now on the advice cards. Every finding leads with a colour-coded error / warn / info chip; the section header gets a category-level breakdown (1 error · 8 warnings · 1 info). The numeric score follows in muted parentheses for error/warn and is hidden entirely for info, where the number isn't a meaningful urgency signal #4667. Rules has been updated to match 2026.
• Browsertime 27 (major). Unified selector syntax for every interaction command (commands.click('#btn'), commands.addText('#input', text)), a much bigger convenience-command surface (type, find, fill, cookie, clickAndMeasure, clickByText, …), Chrome soft-navigation support so SPA route changes produce a HAR page + Core Web Vitals, Safari on iOS over USB (HAR via iwdp, video + visual metrics via CoreMediaIO), and TypeScript navigation scripts on Node 22.18+. See the Browsertime 27 release notes for the full list and the breaking-change details (default --timeouts.elementWait is now 6000ms; clicks now use the Selenium Actions API).
• Coach-core 9 (major). New interactionToNextPaint rule (INP became a Core Web Vital in March 2026), four new modern-image rules (decodingAsync, lazyLoadingImages, modernImageFormats, lcpImageHints), modern privacy/security header rules (Permissions-Policy, X-Content-Type-Options, the cross-origin isolation trio, NEL, Reporting-Endpoints, DOM-side iframeSandbox / referrerPolicy / sessionReplay), CSP scored on its directives instead of its byte length, refreshed thresholds across the rule set, the surveillance category typo fixed (was survelliance), and the package is now ESM-only on Node 20+. See the coach-core 9 release notes.
• HAR waterfalls render via waterfall-tools. The waterfall code moved out of the HTML plugin into the dedicated waterfall-tools package so the same renderer can be reused outside sitespeed.io #4614.
• Compare plugin rewrite. The per-metric scatter plots are now DOM-positioned dots over a relative wrapper (round at any width) with a real Y-axis gutter showing five labelled ticks plus grid lines; setup is split into separate Run-setup and Content-breakdown cards, and the wide stats table scrolls horizontally with paired baseline/current columns #4656.
• Mobile-friendliness pass. Hero KPI bands fit two tiles at a 360px viewport, dt/dd metadata grids stack to one column on narrow screens, and the matched-LCP element image goes fluid-width below 600px #4669.

Breaking

• coach-core bumped to 9.0.0: ESM-only, Node.js 20+, and the survelliance category key in HAR third-party data is now spelled surveillance — consumers that hard-coded the typo need to update #4644, #4666, #4674.
• browsertime bumped to 27: default --timeouts.elementWait changed from 0 to 6000ms (all element commands auto-wait up to 6 seconds for elements to appear; set to 0 to restore old behaviour); click commands now use the Selenium Actions API for real OS-level mouse events instead of .click() so elements must be visible and interactable #4616, #4618, #4621.

Added

• Refreshed look and feel for the report. Implemented across a series of small PRs grouped by area:
  • Summary / Detailed / per-iteration Summary #4622, #4629, #4636, #4670.
  • Metrics tab — LCP, LOAF, INP, CLS, Element Timings, Visual Elements, First Input, Server timings, Visual progress filmstrip #4625, #4626, #4628, #4640, #4641, #4650, #4655, #4663, #4665.
  • Coach tab + sub-pages + severity chips + Help page #4627, #4646, #4667, #4668, #4672.
  • Per-URL tabs — CrUX, Sustainable, Axe, CPU, PageXray, Third-party, Compare, Video #4630, #4631, #4632, #4633, #4634, #4637, #4656, #4657.
  • Top-level result pages — Pages, Toplist, Detailed, Domains, Assets, Errors, Budget #4635, #4658, #4659, #4660.
  • Settings, Screenshots, runtime info, charts, filmstrip and sortable tables #4620, #4638, #4639.
• Detailed-summary hero band picks up the four Core-Web-Vitals-class metrics plus the Coach overall score #4622, #4646.
• Coach severity tier surfaced on every advice card, with a category-level breakdown next to the score chip #4667.
• Google Web Vitals are now a hero card on the metrics tab — each Vital gets a colour-coded dot, the value at 2× the surrounding font size, the short name, and a Good / Needs improvement / Poor label tied to Google's p75 cutoffs. INP suppresses the TBT fallback so we don't show two interactivity proxies side by side. The Visual Milestones tiles next to the chart get a small font bump too #4679.
• "Where the time went" card on the summary tab and per-iteration summary — a stacked horizontal bar splitting the page-load timeline into Network (0 → TTFB), Render-blocking (TTFB → FCP), Largest paint (FCP → LCP) and Tail (LCP → loaded), with a colour legend underneath restating each segment in ms and %. Reads the medians the rest of the summary already uses #4677, #4679.
• Long-task lane on the visual-progress card — one bar per Long Task at its real startTime / duration, tinted by severity (≥ 250 ms red, ≥ 100 ms amber, otherwise pale amber) so the worst offenders pop visually next to the FCP / LCP markers #4678.
• Visual-metrics tab gains a hint that points at --cpu when the FCP / LCP recalculate-style breakdowns aren't available, so it's clear how to enable them rather than leaving the card silent #4673.

Changed

• coach-core bumped from 9.0.0-beta.1 to 9.0.0 #4674.
• browsertime bumped to 27.0.4 — Safari iOS video time-scale fix (default capture rate is now 60 fps so visualmetrics-derived metrics match the browser's wall-clock timeline) #4676.
• axe-core bumped to 4.11.4 #4662.
• HAR waterfalls render via the dedicated waterfall-tools package instead of inline JS #4614.
• Chartist (and its three plugins) dropped from the report assets — the visual-progress chart and the compare scatter plots are now inline SVG / DOM-positioned #4654, #4655, #4656.
• Unify quicklinks across tabs around a consistent <small> + | separator with a fixed leading-pipe-spacing bug #4664.
• CI hardened with step-security/harden-runner #4610, action SHAs pinned #4606, CI sped up #4617. The apt-built SSH test container in the upload workflow replaced with lscr.io/linuxserver/openssh-server so the job stops flaking on Ubuntu mirror outages #4661.

Fixed

• INP card guards against missing fields on the interaction target #4652.
• LCP card guards against undefined url and id #4651.
• index.pug no longer crashes when HERO_URLS is referenced before block content #4624.
• CLS shows in the summary even when the value is 0 #4623.
• The "limited metrics on Safari" warning only shows on desktop Safari, not iOS #4648.
• Long Firefox preference identifiers wrap inside settings tiles #4647.
• Solid warning pills are now bright yellow instead of a muted pastel that read as "ok" #4645.
• Capped the matched-LCP element image preview so a 1200×800 hero photo doesn't dwarf the rest of the card #4642.
• The visual-progress card no longer renders DCL on a chart of "what the user sees" — it's a DOM lifecycle event, not a visual one. Replaced with VisualComplete85 #4655.
• Several typos in the report (page titles, in-page text, anchor ids) #4649, #4671, #4672.
• Polish across the report — odds and ends #4643.
• Re-enable the Coach for --safari.ios runs (the legacy carve-out that disabled it is no longer needed) and cap the LCP / CLS / iteration screenshot heights so portrait iPhone captures don't dwarf the rest of the card #4675.