# Page snapshots — auditing a real page, offline A **capture** (`render --setup`) is a rendered *component*. A **snapshot** is a rendered *page*: the whole document as the browser built it, plus the signals only a browser has (computed styles, boxes, accessibility tree, a screenshot), stored on disk so the static engine can re-audit it later with **no browser**. That difference is not cosmetic. It is what makes a whole class of criteria decidable. ``` .ultra11y/pages// meta.json page identity: id, name, url, route?, auth?, viewport?, sources? dom.html documentElement.outerHTML, prefixed with the usual capture comment styles.json computed-style digest, joined to the DOM by document-order index boxes.json bounding boxes, same join key css.json the page's own stylesheets (rules + declarations), NOT element-indexed axtree.json the accessibility tree, when a producer supplies it (no rule reads it yet) probes.json what the LIVE probes measured here — and `probed`, which ones actually ran axe.json the axe pass that ran beside them (`ran: true` is what makes its silence usable) screen.png viewport screenshot (pixel tier) ``` The last two are the measurement half, and they are what lets a page CONCLUDE rather than merely report. `renderedProvesOn` reads `pageCoverage.scs` / `.axe`, both derived from them, so a page with no `probes.json` can raise a rendering non-conformity and can never earn a rendering conformity — 1.4.4, 1.4.10 and 1.4.12 have no offline rule at all, and 1.4.3's canonical decider is axe. `probed` is written only for a probe that really ran: one that threw, a viewport that would not resize, an override that would not apply — none of them reach it, because their silence is not a measurement. `audit` ingests `.ultra11y/pages` automatically, exactly as it ingests `.ultra11y/captures` (`--no-captures` opts out of both). Nothing new to run: ``` node scripts/ultra11y.mjs audit "src/**/*.tsx" --jsx # snapshots folded in automatically ``` ## Why a snapshot decides more than a capture A component capture is a **fragment**: no ``, no ``. The engine's `scope: "page"` rules are deliberately skipped on fragments (`isFullDocument`), because a `