| # Largest Contentful Paint bug in Chrome 140 |
| |
| A bug was introduced in Chromium 140 that caused the presentation time for some |
| web page text to be reported earlier than it should have been. More |
| specifically, when the presentation time was received for any text element, that |
| timestamp was used for all painted text elements whose presentation time had not |
| yet been set. This could cause text painted in quick succession of other text to |
| have a presentation timestamp that too early, typically about one animation |
| frame vsync interval, but potentially more in some cases. The bug impacted CrUX |
| data, web-exposed LCP entries, and ElementTiming entries. |
| |
| The bug was [reported](https://issues.chromium.org/issues/455791378) and fixed |
| in Chromium 143, which was released to Stable in December 2025. |
| |
| ## How does this affect a site's metrics? |
| |
| As a result of this issue, LCP may have erroneously appeared to improve between |
| Chromium 140 and 142, inclusively. This only affected sites whose LCP element is |
| text, and only in cases where the LCP element was painted soon after having |
| painted other text elements, in another animation frame. The impact for such |
| sites is expected to typically be on the order of dozens of milliseconds, but |
| some variation is expected. |
