5.19.0 (2026-08-11)

Variable Row Height

This new release brings a feature that was requested by SlickGrid's users for many years, we now have the possibility to use Variable Row Height (thanks to Ben (aka 6pac), for his promo access to Claude Fable 🤖). This feature does have some small perf impact (e.g. scroll position must be calculated differently) and so it is opt-in, you will need to enable it before you can use it and you have 2 possible ways of defining variable row height (see both examples below)

1. rowHeightProvider grid option
2. item metadata height property

See 3 new examples:

• Variable row height (rowHeightProvider)
• Variable row height with cell spans (rowHeightProvider + enableCellRowSpan)
• Variable row height with frozen columns/rows (rowHeightProvider + frozenColumn/frozenRow)

RTL Support

Another thing that is worth mentioning is the PR to improve RTL (right to left) support. Thanks to @jahanbakhsh18 for the help in improving this

• Basic use with RTL support

Also thanks to @muendlein for other fixes as well related to column resizing

Bug Fixes

• 'getColContentSize' for single row with 0 as value (#1222) (dc17328)
• align frozen-band cell-cleanup ranges with the (inclusive) render ranges (#1259) (b878c6b)
• autosize never measured autoSize.colValueArray (#934) (#1273) (10e2e0a)
• canonicalize the frozen-row boundary across all comparison sites (#1268) (bd2b6b6)
• CellExternalCopyManager shouldn't throw when out of bound (#1226) (0f09f11)
• core: compute scrollTo page before deriving the paging offset (#1231) (1a7fcc5)
• core: probe positioned-child limit in getMaxSupportedCssHeight (#1232) (dddaed4)
• core: small type casting fix to value passed to applyHtmlCode() (#1248) (0b41d59)
• decode clipboard paste on delivery instead of a fixed delay (#1261) (20fc9a8)
• examples: deterministic seeded data in checkbox-header-row example (#1246) (f015e96)
• footer-row lifecycle - construction crash, inconsistent getFooterRow, double onFooterRowCellRendered (#1256) (2dc065c)
• fractional grid height leaves the bottom rows unrendered (#1262) (#1263) (a9c261c)
• frozen-bottom grids never clean up off-screen row cells (#1255) (214dcf1)
• frozen-bottom hit testing resolves the wrong row when data is shorter than the viewport (#1258) (6d39e14)
• route off-viewport alwaysRenderColumn cells to their own column band (#1267) (306e972)
• treat frozenRow: 0 as no freeze (input clamp) (#1266) (d61fc56)
• updateRowPositions leaves right-pane row fragments at stale positions (#1257) (f254ac8)

Features

• add core RTL support for headers and column resizing (#1271) (7b2e337)
• build the footer row lazily when createFooterRow is enabled at runtime (#1269) (a73d083)
• core: add variable row height support via rowHeightProvider (#1235) (c49ab66)

Performance Improvements

• Enhance performance content size calculation, fixes #1223 (#1224) (9de774b)