UV Strecthing

Is there any addons or a way to view stretching.
Some software will show blue is stretching and red is crunched. How do I know if my island is oversized in proportion?
I do my uv’s in Blender.
Sometimes I do my texture map first. Maybe I should do the uv first.
So I check with the square uv grid for help. I really don’t see any stretching.
I then Import to another software and I get blues and reds!!

Activate “Stretch” in the N-panel display options:

Under that checkbox you can choose between angular and areal stretch.

Wow, works fine!! Thank you.
Well while I’m on uv’s here.
I was also wondering about making wavy lines straight like shown in the image.
A better way than manually editing 1 vertice at a time?
Not that bad in the image but just an ex…

Looptools Gstretch addon includes this function as aone click, enhanced even more as of a few days ago…

But you can do it with vanilla Blender by scaling to zero along an axis. Defining the space to scale in is a matter of picking some element and creating a custom orientation using it.

For instance I could pick the center vertex and create a new transform orientation with ctrl alt spacebar. (check use after creation in the operator panel or F6 dialog, or pick it in the Npanel on the right or from the transform orientation menu in the header) If your manipulator is showing you can see which axis to scale in; for example ‘S’ ‘Z’ ‘Z’ will bring all selected vertices into a straight line with the active vertex at the center along ITS Z axis. Takes much longer to describe in words than to do.

Well was a good day to learn some uv!! Thx for the help and comments. I know what you mean by the scaling it gets close. I used it that before. Never mastered it…
There’s the align auto like you mentioned. Which is super fast!! Have to realize the hotkeys for the UV editor also!! Actually it is in the Weld/Align uv menu also.

Wow, I really should read more carefully or sleep more! I did not register that your screenshot was of UVs, not vertices, and the things I suggested (LoopTools, Custom orientations) only apply to mesh not UVs. Except for the scale.

Mea culpa. Sorry for the idiocy! Ignore if possible.