AJAX page: Identify time-consuming calls

Our browser monitoring's AJAX UI shows recent AJAX requests from browsers to external endpoints, such as HTTP or HTTPS domains. This information helps identify problems with the end user experience when you have time-consuming or failing AJAX calls that update parts of a webpage on your site.

What to troubleshoot

Here are some troubleshooting tips for identifying performance problems with your app:

Troubleshooting AJAX calls Examples
Problems across the entire request

If you're not sure where the problem is, or if you want to trace your requests from start to finish, click the distributed tracing link in the AJAX UI.

Timing problems

Total time percentages, throughput requests per minute (rpm), and average data transfer rates per request can help identify timing problems.

  • Look for large spikes in the AJAX summary page's Average data transfer per request chart.
  • From the individual call's AJAX performance tab, look for correlations between high callback time values and data transfer rates.
Endpoint problems

Look for any outlier endpoints, and investigate individual requests made from them.

The Status codes chart on the AJAX summary page provides information about the return behavior from the call. If you see a large number of status codes outside the 200 range, this may indicate a problem with your AJAX endpoints.

Specific webpage location problems

Examine potential AJAX problems within the context of the page where they load. Select an AJAX transaction, then select any trace from the Session traces with AJAX table.

How to do it

To troubleshoot problems with AJAX requests for your app:

NR One browser monitoring: AJAX summary
one.newrelic.com > Browser > (select an app) > AJAX: Identify problems due to time-consuming or failing AJAX calls that update parts of a webpage on your site.
Start with AJAX summary charts

The summary page provides several charts to help you troubleshoot AJAX calls.

AJAX summary page Comments
Groups and filters

Use any of the available Sort by or filter options in the UI. All AJAX requests that take longer than two minutes are filtered out automatically.

You can also group your browser metrics by URLs. For example, this is useful with allow lists and deny lists.


The Throughput chart shows the five endpoints with the highest throughput. If the call has more than five endpoints, they are consolidated on the chart as Other.

Calls from New Relic

You may see our own browser monitoring AJAX calls to your app. This is normal, because all activity is captured during the browser session.

Missing browser data

AJAX timing details are not available from IE 7, IE 8, or Chrome for iOS browsers. If you do not see expected data from other browsers, follow our AJAX troubleshooting procedures.

Get details by calls or page views

After selecting a specific call from the AJAX summary page, you can drill down into detailed information with the AJAX performance tab. This includes a direct link to session trace details.

From here you can also select the tab to get performance data by page views. (If your app server requests greatly outnumber your browser PageView transactions, this is because some requests to your back end are made through AJAX. For more information, see our troubleshooting procedures.)

NR One browser monitoring: AJAX details
one.newrelic.com > Browser > (select an app) > AJAX > (select an AJAX call): This example shows performance details for a specific AJAX call. You can also view performance details by page views.

AJAX endpoints on the Average response time chart appear either as four or two time periods. This depends on whether there are cross application tracing headers.

  • Four time periods (Application time, Queue time, Network time, and Callback time): These AJAX calls are made against apps monitored by APM agents that provide cross application tracing headers.
  • Two time periods (Response time and Callback time): These AJAX calls are made against apps that either are not monitored by APM agents, or they are monitored by agents that do not provide cross application tracing headers.
Trace your requests from start to finish

To trace your requests from start to finish, you can also click the distributed tracing link in the AJAX UI.

  • To view a list of distributed traces, click the link in the AJAX UI at the AJAX summary level.
  • To view all traces filtered by your application and a specific request type, click the distributed tracing link for the request you select in the AJAX UI.
Time percentage example

When you sort the AJAX category list by Total time percentage, the list shows the percentage for each AJAX category. Also, the chart shows the top requests with the highest time percentages.

To present this information, Browser takes the cumulative request time for each AJAX category and divides it by the cumulative request time for all AJAX requests. This helps identify where to optimize response times, because high throughput requests will be favored over low throughput requests.

Example: Calculating time percentages for two AJAX categories

This example uses two AJAX categories: api1.example.com and api2.example.com.

  • Your api1.example.com is hit 1 time, and it takes 1 second (1000ms) to respond (1 x 1 second = 1 second).
  • Your api2.example.com is hit 500 times, and it takes 1ms to respond (500 x 1ms = 500ms, or 0.5 second).

The cumulative request time for all of your AJAX categories is 1500 ms, or 1.5 seconds. To get the time percentages, divide each AJAX category by the cumulative request time, and then multiply by 100 for the percentage.

So api1.example.com is 67% (1000 divided by 1500, times 100) and api2.example.com is 33% (500 divided by 1500, times 100) of the total time percentage.

Time calculations api1 api2
Number of hits 1 500
Time to respond

1 second (1000ms)

1 hit x 1000ms = 1000ms (1 second)

1 millisecond (1ms)

500 hits x 1ms = 500ms (.5 second)

Cumulative request time for all AJAX categories 1000ms + 500ms = 1500ms (1.5 seconds) 1000ms + 500ms = 1500ms (1.5 seconds)
Time percentage = Category / 1500ms cumulative request time x 100 for percentage 1000ms / 1500 x 100 = 67% 500ms / 1500 x 100 = 33%

What's next

In addition to the AJAX UI, you can also use these resources:

For more help

If you need more help, check out these support and learning resources: