Bug 157203 - Typing is really slow when there are many input text fields with values
Summary: Typing is really slow when there are many input text fields with values
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: Safari 10
Hardware: Macintosh macOS 10.12
: P2 Normal
Assignee: Nobody
Keywords: InRadar
Depends on:
Reported: 2016-04-29 14:44 PDT by David Gasperoni
Modified: 2017-10-26 14:32 PDT (History)
14 users (show)

See Also:

Test case (3.34 KB, text/html)
2016-07-20 01:25 PDT, David Gasperoni
no flags Details

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Description David Gasperoni 2016-04-29 14:44:41 PDT
When there is a huge amount of input fields on a page, the typing performance is very bad. Such pages do exists, for example string translation backends with collapsable fieldsets for each single set/page to translate. In this cases the PHP backend even needs to increase the max_input_vars.

I created a page that shows how even on a current MBP Retina, performance is terrible. https://gist.github.com/mcdado/35d8ccb3d5c165c28ed6f70ffca68948

Also, after a while fans start spinning up and they wind down only when the backlog of typed characters are displayed. I made a video here comparing performance with latest Firefox 48, Chrome 50, and Safari Technnology Preview 3: http://cl.ly/0v1g3a3P3h3o

I hope this helps!
Comment 1 Andreas Kling 2016-04-29 16:55:49 PDT
This seems to be happening due an issue in Safari's form auto-fill mechanism. Apple people can see <rdar://problem/8555317> for more information.
Comment 2 David Gasperoni 2016-07-20 00:58:59 PDT
Any news about this? Performance still sucks in this use case.
Comment 3 David Gasperoni 2016-07-20 01:25:52 PDT
Created attachment 284093 [details]
Test case

1. Input any high number
2. Click GO
3. Try to type in the text fields

What do i see? It's extremely slow and laggy.

What is the expected result? Fast and snappy.
Comment 4 David Gasperoni 2017-03-23 12:37:43 PDT
Still an issue in Safari Technology Preview release 26.
Comment 5 Radar WebKit Bug Importer 2017-03-23 19:23:20 PDT
Comment 6 Andreas Kling 2017-03-23 19:30:28 PDT
The correct radar number is <rdar://problem/21705952>
Comment 7 Simon Fraser (smfr) 2017-04-05 13:13:27 PDT
rdar://problem/21705952 was used to fix an issue on https://www.boe.ca.gov/trace/report/ on pages having <select>s with lots of options.

This bug now corresponds with rdar://problem/31460933.
Comment 8 David Gasperoni 2017-05-10 03:02:32 PDT
Since release 29 of Safari TP things seems to be much better! Still there is an initial delay when starting to type, and changing fields also has a noticeable delay.
Comment 9 Steffen Weber 2017-10-05 03:52:30 PDT
Safari 11 handles the attached test-case better but only because the input fields don't have a "value" attribute. Adding the attribute value="123" to the input fields immediately makes the test-case unusably slow even in Safari 11.

Could somebody please have a look at this issue?
Comment 10 Darin Adler 2017-10-26 09:45:02 PDT
Itβ€˜s a bit frustrating to have this in the WebKit bug tracker since there is no problem in WebKit clients other than Safari. I believe this is a Safari problem and should not be tracked with an open WebKit bug.