Map Viewer is slow, including setting default visualization

[AlfredBaldenweck]

Does anyone have any suggestions for making new Map viewer not be so slow?

This seems to be a recurring issue. I like a lot of Map Viewer's functionality, but I really am having a hard time waiting for it to do anything.

It is painful to try to make any changes to a map, such as filtering or changing symbology. Forget editing. I understand it on maps with a bunch of stuff, but it's even affecting setting visualization for feature classes on their own item page. I just set symbology for an empty feature class and it took forever to load. I do not mean the map, I mean each menu when you click on it or make any changes.

I'm also confused because all of the applications that use the maps don't seem to have any slowness? Collector/FieldMaps has no problem, for example. Just Map Viewer seems to be slow.

If anyone has any tips for making it not so slow, I'd appreciate it. Thanks!

[RussRoberts]

If you can share the map you are seeing the issue with we can take a look at it. thanks!

[Gjermund]

The maps are not publicly available, but I have already shared data to recreate the maps  in support case 03527993 - related to the bug from my previous post.

[AspenN]

Anyone else experiencing this issue in Enterprise 11.3? We noticed a significant decline in loading performance for Map Viewer upon upgrading from 11.2 to 11.3. The slowness gets worse the more layers that are added. This only occurs in Map Viewer not Map Viewer Classic.

[Ole_MariusGulbrandsen]

Were still having major performance issues with the new Map viewer, with the february 2025 update  you also have to scroll trough all the sublayers in the layer groups if you add a new layer to the project and want to move it down or up in the content pane. The map is being used in interdisciplinary project work with a lots of layers and sublayers, so this new bug makes it more difficult to maintain and update these projects. Opening the same map in Experience builder for some reason run much smoother 

[RussRoberts]

The expanding on the layer list behavior group layers is currently as designed but we have sent this feedback over to the team. You will also see this on Experience Builder with an app that allows reordering. You can also use the overflow action and select Move and pick the group or clicking on the drag handle will also give you the option to move to group layers.

We still have some performance updates on the roadmap for differences between the two if you can share the map I will take a look. 

[DanLissick]

I am seeing the same issue. Below is the response I received from Esri:

SummaryDocumentation:

• The information we received from internal is that this behavior is expected with 4x (i.e., the Maps SDK for JavaScript). Complex polyline and polygon layers are generalized to improve query time. This is different than 3x which loads these geometries differently.
• We also see layers be generalized/optimized by default when they have more than 400,000 vertices to protect the organization's datastore. This is mentioned in our documentation here:
  •  Manage hosted feature layers—ArcGIS Online Help | Documentation.
• From the example layer with which we've reproduced the behavior with in-house, we observed that it's a complex polyline layer that by default, has been optimized by the software upon publishing.
• In general, we have the mantra of no more than one vertex per pixel at any particular scale, meaning that data is being generalized dynamically when being viewed. This isn't bluntly stated in our documentation anywhere, but this topic is touched on in the video resource linked below. Note the discussion at about 24:50 minutes in.
  • Optimize ArcGIS Online Maps and Apps for Audiences of Any Size - Esri Videos: GIS, Events, ArcGIS Pr... 
• This blog also touches on a similar topic of discussion:
  • Essential Configurations for Scalable ArcGIS Online Web Applications.
• My colleague that I was working with has mentioned to internal that the difference between 3x and 4x loading should be documented somewhere - but they would also encourage you to leave feedback directly on our documentation using the 'feedback on this topic?' option on the Map Viewer documentation page as well.
• Additionally, the reason that ArcGIS Field Maps and our other Mobile applications do not display the same behavior is because our mobile apps are not built on the same code base - JavaScript is used for web clients while our mobile apps use a product called ArcGIS Runtime or ArcGIS Maps SDKs for Native Apps | Documentation | Esri Developer.
• The existing Enhancement requesting an improvement in how Map Viewer renders features upon zoom in is ENH-000163087, and has been attached to this case.

I've also provided the feedback you passed along to me in regards to this change and inquired regarding if escalating an Enhancement is possible.

Unfortunately there isn't a set process of escalating an Enhancement in the same way that bugs can be escalated - Our bug escalation documentation page states this directly. However some indirect methods of escalating it would include creating a post on our ArcGIS Ideas forum, which can bring additional views and attention to the issue as our development team does browse the ArcGIS Ideas forum. If you do end up doing this, if you can provide me with the link to the Ideas Page, I can directly attach it to the Enhancement to route other users that create cases for this issue to the same enhancement number.