We had to change our front page, but here is a simplified example of this bug:
https://codepen.io/anon/pen/XZJzQm

It produces the same "effect" as the original example url.

Thanks for the repro. I think I have narrowed it down to it being related to the fractional blur. Simply alternating the blur value between 0.2px and 0px achieves the same effect which visually looks like the text is larger than usual.

Here is my simplified repro: http://jsbin.com/pupasem/edit?html,css,js,output


This is not really related to any animation machinery. Updating the component for further triage. 

The effect slightly more pronounced: http://jsbin.com/pupasem/2/edit?html,css,js,output

Thanks, but your fiddle is different in Chrome Canary 66.0.3334.0 as it seems like it does nothing.

In Chrome 64.0.3282.119, your example jumps back and forth, so I think your code shows this bug: https://bugs.chromium.org/p/chromium/issues/detail?id=795528#c25


Here is my example based on yours:
https://jsfiddle.net/g27zuvt3/1/

If you change the max value which is the maximum amount of blur lower than 4.7, then you won't see anything strange in Canary. If it is 4.7 or more, Canary jump before it reaches the 0 state. So I think this is the example which related to this bug.

I think I can reproduce this issue.

A few frames prior to the end of the transition, there appears to be some sort of stretch occurring on the element. I've attached some videos and images demoing the issue in detail. Notice how the box seems to get a "border", and the 'W' in Western and the last 'a' in Australia get stretched during the issue.

A cut down example of my repro is available here: http://jsbin.com/dibexew

What's also interesting is it doesn't occur every single time, I had to hover over the element a few times to get it to occur.

Description of attachments:

BlurStretchIssue-FullSpeed.mp4 - A real time copy of the footage cropped and scaled to the area of interest.

BlurStretchIssue-0.05x.mp4 - A slowed down copy (20x slower) of the footage cropped and scaled to the area of interest. You'll notice that the issue occurs at exactly frame 27, lasts 3 frames, and then disappears at frame 30. (Note: These frames are not browser animation frames, rather frames out of my video. I tried to get the best recording I could, but they may not line up perfectly with browser draws).

BlurStretchIssue-0.1x.mp4 - This is a version I recorded in real time, however I've used the animation developer tools to slow all animations down to 10%. An interesting thing to note here is that, even tho the animation is running at 10% speed, the issue still occurs for the same duration as the animation running at 100% speed.

BlurStretchIssue-FrameBefore.png - This is the exact frame before the issue occurs
BlurStretchIssue-FrameDuring.png - This is the exact frame during the issue
BlurStretchIssue-FrameAfter.png - This is the exact frame after the issue occurs

It's difficult to get a good bisect, but the last good version I was able to determine was 505174, which says to me it was introduced around the same time as https://bugs.chromium.org/p/chromium/issues/detail?id=795528.

If you need any more information, let me know.

Deleted: BlurStretchIssue-FullSpeed.mp4 567 KB

	BlurStretchIssue-FullSpeed.mp4 567 KB View Download

Deleted: BlurStretchIssue-0.05x.mp4 2.0 MB

	BlurStretchIssue-0.05x.mp4 2.0 MB View Download

Deleted: BlurStretchIssue-0.1x.mp4 1.4 MB

	BlurStretchIssue-0.1x.mp4 1.4 MB View Download

Deleted: BlurStretchIssue-FrameBefore.png 844 KB

	BlurStretchIssue-FrameBefore.png 844 KB View Download

Deleted: BlurStretchIssue-FrameDuring.png 835 KB

	BlurStretchIssue-FrameDuring.png 835 KB View Download

Deleted: BlurStretchIssue-FrameAfter.png 828 KB

	BlurStretchIssue-FrameAfter.png 828 KB View Download

Able to reproduce this issue with link given in comment#4,#7 and comment#8.i.e; Unwanted stretch of font is seen. But issue is inconsistent while bisecting.

CC'ing author from  issue 795528  for further inputs on this.

@herb: Please help in assigning to correct owner if it has nothing to do with your change.

Thanks! 

This is another example of the remaining issues with blur filters at very small radii. It's not fixed and it does not appear to be a site error.

Just a heads up that Chrome 66 broke this even further. If you take a look at my example in #8, now on hover the element briefly flashes to the "end frame" of the transition, before playing out the full transition. Compare to the current version of Firefox for the proper behavior.