232176 2021-10-22 14:21:30 -0700 Improve performance of nested grids 2026-02-01 16:01:50 -0800 1 1 1 Unclassified WebKit Layout and Rendering WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 304869 https://bugs.webkit.org/show_bug.cgi?id=125145 https://bugs.webkit.org/show_bug.cgi?id=268595 https://bugs.webkit.org/show_bug.cgi?id=271083 https://bugs.webkit.org/show_bug.cgi?id=269558 https://bugs.webkit.org/show_bug.cgi?id=302529 https://bugs.webkit.org/show_bug.cgi?id=304869 InRadar P2 Normal --- 1 ntim sgill26 ahmad.saleem792 bfulgham cathiechen dobiasch maggotfish mattwoodrow mendelgordons michael.zacharov punit.rathod rbuis rego rik sgill26 simon.fraser svillar tobias47n9e webkit-bug-importer zalan zsun oldest_to_newest 1807880 0 ntim 2021-10-22 14:21:30 -0700 See: http://exponential-layout.glitch.me From: https://developer.chrome.com/blog/layoutng/ 1810245 1 webkit-bug-importer 2021-10-29 14:22:19 -0700 <rdar://problem/84823492> 1900621 2 dobiasch 2022-09-23 06:17:49 -0700 Safari 16 – still present – 15+ nested grids and the cpu is stalling 1980978 3 michael.zacharov 2023-09-28 08:08:40 -0700 Safari 17 – still present – 15+ nested grids and the cpu is stalling 2012683 4 mendelgordons 2024-02-12 06:33:35 -0800 See https://web.archive.org/web/20211008182612/https://developer.chrome.com/blog/layoutng/ since the original link is dead (In reply to Tim Nguyen (:ntim) from comment #0) > See: http://exponential-layout.glitch.me > > From: https://developer.chrome.com/blog/layoutng/ 2012707 5 tobias47n9e 2024-02-12 08:12:01 -0800 Just a comment regarding importance: Would be nice to see this get higher priority. Grid is used for so many layout problems now, and the developer pain of having to remove all that just for Webkit based browsers is incredible. 2024027 6 ahmad.saleem792 2024-03-26 14:56:12 -0700 I tested this post 276633@main and now this test can be pushed to 100+ without any issue on M1 Pro with 16 GB. Change progressing this - https://commits.webkit.org/276633@main @Sammy - should we mark this duplicate of other bug? 2026699 7 rego 2024-04-08 01:38:02 -0700 (In reply to Ahmad Saleem from comment #6) > I tested this post 276633@main and now this test can be pushed to 100+ > without any issue on M1 Pro with 16 GB. > > Change progressing this - https://commits.webkit.org/276633@main > > @Sammy - should we mark this duplicate of other bug? I can confirm this behavior, without that patch my computer starts to struggle around adding the 15th layer (or earlier). With that patch I've managed to add >150 layers easily. 2159224 8 punit.rathod 2025-11-17 02:28:01 -0800 Safari 26 – still present. It would be good if this bug could be prioritised. We had a product which was shifting over to use a new grid layout system. Everything was fine on Chrome and Firefox. The whole site became unresponsive on Safari - spinning ball on intel CPU and extreme lag on M1 CPU. The UI refresh had to be abandoned and reverted to the old UI not using nested grids. 2159225 9 477416 punit.rathod 2025-11-17 02:29:56 -0800 Created attachment 477416 Simple html example causing extreme lag in Safari 2159250 10 zalan 2025-11-17 05:45:09 -0800 I can reproduce this. Sammy, any thoughts? 2159321 11 sgill26 2025-11-17 11:03:19 -0800 Yeah I can still reproduce too. It seems like there might be a couple of different issues still going on so I'll try to look into them individually but I don't have any additional information right now. 1.) Increasing span size for the subgrid makes the page take longer to load 2.) Increasing number of subrows in the content increases the resizing jank 2173370 12 sgill26 2026-01-20 10:07:16 -0800 I believe this should be significantly progressed on trunk as of 305121@main. Could you please test and see if you are still able to reproduce the issue? *** This bug has been marked as a duplicate of bug 304869 *** 477416 2025-11-17 02:29:56 -0800 2025-11-17 02:29:56 -0800 Simple html example causing extreme lag in Safari nested_grid_performance_issue_example.html text/html 2007 punit.rathod PGh0bWw+CiAgPGhlYWQ+CiAgICA8c3R5bGUgdHlwZT0idGV4dC9jc3MiPgoKICAgICAgLmdyaWQg ewogICAgICAgIGRpc3BsYXk6IGdyaWQ7CiAgICAgICAgZ3JpZC10ZW1wbGF0ZS1jb2x1bW5zOiBh dXRvOwogICAgICB9CgogICAgICAuc3ViZ3JpZCB7CiAgICAgICAgZGlzcGxheTogZ3JpZDsKICAg ICAgICBncmlkOiBzdWJncmlkIC8gc3ViZ3JpZDsKICAgICAgICBncmlkLWNvbHVtbjogMSAvIC0x OwogICAgICAgIGdyaWQtcm93OiBzcGFuIDMwMDAgLypJTkNSRUFTRSBGT1IgTU9SRSBKQU5LKi8K ICAgICAgfQoKICAgICAgLnN1YnJvdyB7CiAgICAgICAgZGlzcGxheTogZ3JpZDsKICAgICAgICBn cmlkLXRlbXBsYXRlLWNvbHVtbnM6IHN1YmdyaWQ7CiAgICAgICAgZ3JpZC1jb2x1bW46IDEgLyAt MTsKICAgICAgfQoKICAgIDwvc3R5bGU+CiAgPC9oZWFkPgoKICA8Ym9keT4KICAgIDxkaXYgY2xh c3M9ImdyaWQiPgoKICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlkIj4KICAgICAgICAgICAgPGRp diBjbGFzcz0ic3Vicm93Ij4KICAgICAgICAgICAgICAgIDx0ZXh0YXJlYT5SZXNpemUgbWUgaW4g U2FmYXJpIHRvIHNlZSBqYW5rLjwvdGV4dGFyZWE+CiAgICAgICAgICAgIDwvZGl2PgogICAgICAg IDwvZGl2PgoKICAgICAgICA8IS0tIEFERCBST1dTIEZPUiBNT1JFIEpBTksgLS0+CiAgICAgICAg PGRpdiBjbGFzcz0ic3ViZ3JpZCI+PGRpdiBjbGFzcz0ic3Vicm93Ij5Sb3c8L2Rpdj48L2Rpdj4K ICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlkIj48ZGl2IGNsYXNzPSJzdWJyb3ciPlJvdzwvZGl2 PjwvZGl2PgogICAgICAgIDxkaXYgY2xhc3M9InN1YmdyaWQiPjxkaXYgY2xhc3M9InN1YnJvdyI+ Um93PC9kaXY+PC9kaXY+CiAgICAgICAgPGRpdiBjbGFzcz0ic3ViZ3JpZCI+PGRpdiBjbGFzcz0i c3Vicm93Ij5Sb3c8L2Rpdj48L2Rpdj4KICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlkIj48ZGl2 IGNsYXNzPSJzdWJyb3ciPlJvdzwvZGl2PjwvZGl2PgogICAgICAgIDxkaXYgY2xhc3M9InN1Ymdy aWQiPjxkaXYgY2xhc3M9InN1YnJvdyI+Um93PC9kaXY+PC9kaXY+CiAgICAgICAgPGRpdiBjbGFz cz0ic3ViZ3JpZCI+PGRpdiBjbGFzcz0ic3Vicm93Ij5Sb3c8L2Rpdj48L2Rpdj4KICAgICAgICA8 ZGl2IGNsYXNzPSJzdWJncmlkIj48ZGl2IGNsYXNzPSJzdWJyb3ciPlJvdzwvZGl2PjwvZGl2Pgog ICAgICAgIDxkaXYgY2xhc3M9InN1YmdyaWQiPjxkaXYgY2xhc3M9InN1YnJvdyI+Um93PC9kaXY+ PC9kaXY+CiAgICAgICAgPGRpdiBjbGFzcz0ic3ViZ3JpZCI+PGRpdiBjbGFzcz0ic3Vicm93Ij5S b3c8L2Rpdj48L2Rpdj4KICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlkIj48ZGl2IGNsYXNzPSJz dWJyb3ciPlJvdzwvZGl2PjwvZGl2PgogICAgICAgIDxkaXYgY2xhc3M9InN1YmdyaWQiPjxkaXYg Y2xhc3M9InN1YnJvdyI+Um93PC9kaXY+PC9kaXY+CiAgICAgICAgPGRpdiBjbGFzcz0ic3ViZ3Jp ZCI+PGRpdiBjbGFzcz0ic3Vicm93Ij5Sb3c8L2Rpdj48L2Rpdj4KICAgICAgICA8ZGl2IGNsYXNz PSJzdWJncmlkIj48ZGl2IGNsYXNzPSJzdWJyb3ciPlJvdzwvZGl2PjwvZGl2PgogICAgICAgIDxk aXYgY2xhc3M9InN1YmdyaWQiPjxkaXYgY2xhc3M9InN1YnJvdyI+Um93PC9kaXY+PC9kaXY+CiAg ICAgICAgPGRpdiBjbGFzcz0ic3ViZ3JpZCI+PGRpdiBjbGFzcz0ic3Vicm93Ij5Sb3c8L2Rpdj48 L2Rpdj4KICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlkIj48ZGl2IGNsYXNzPSJzdWJyb3ciPlJv dzwvZGl2PjwvZGl2PgogICAgICAgIDxkaXYgY2xhc3M9InN1YmdyaWQiPjxkaXYgY2xhc3M9InN1 YnJvdyI+Um93PC9kaXY+PC9kaXY+CiAgICAgICAgPGRpdiBjbGFzcz0ic3ViZ3JpZCI+PGRpdiBj bGFzcz0ic3Vicm93Ij5Sb3c8L2Rpdj48L2Rpdj4KICAgICAgICA8ZGl2IGNsYXNzPSJzdWJncmlk Ij48ZGl2IGNsYXNzPSJzdWJyb3ciPlJvdzwvZGl2PjwvZGl2PgoKICAgIDwvZGl2PgogIDwvYm9k eT4KCjwvaHRtbD4K