Does Intercom slow down your landing page? Chat widgets are some of the heavier scripts. Start them later.

What the data shows for Intercom and other chat

The numbers come from third-party-web, an open dataset by Patrick Hulce built from HTTP Archive's Lighthouse runs across millions of pages on mobile settings. How that dataset is made, and the full list of scripts, is in third-party scripts and landing page speed.

We used third-party-web version 0.30.0, published in September 2026, with the HTTP Archive crawl from March 1, 2026. For Intercom it reports:

• Average script execution time: 1,433 ms per page.
• Usage: 58,316 pages in the crawl.

The dataset counts each vendor's own domains together, so a chat tool's number covers its widget and the messenger it loads behind the bubble. Other chat tools in the same crawl:

HubSpot's chat is counted inside HubSpot's full row, which also holds tracking and forms, so it is not listed here. See does HubSpot slow down your landing page and the full list in third-party scripts and landing page speed.

What script execution time means for a phone visitor

A phone browser does most of its work in one lane, called the main thread. That lane builds the page, runs scripts, and answers taps. Only one job runs there at a time.

Google's Lighthouse docs say that when the main thread is busy, the page can't respond to user input. Google's Interaction to Next Paint (INP), a Core Web Vital, measures how long a tap waits for an answer. Google rates INP good at 200 ms or less and poor above 500 ms. Every millisecond a script spends on the main thread is a millisecond a tap on your call button can wait.

A chat widget is a small app. It loads its code, checks for old conversations, and draws a bubble. If all of that runs while the page loads, it competes with your headline and your call button for the same lane.

How to load chat the smart way

1. Boot it after the visitor interacts

Intercom's developer docs say that if you want to control when Intercom is loaded, you can use the boot method. Instead of starting the Messenger on page load, start it after the visitor's first scroll or tap, or a few seconds after the page finishes loading. The page gets usable first. The bubble shows up a moment later for the people who stay.

Using a different chat tool? Look in that vendor's own docs for a way to control when it loads, and test that chat still opens after the change.

2. Ask who answers it

Chat helps when a person replies fast. A homeowner with a leaking pipe will not wait twenty minutes for a reply. If nobody watches chat after hours, the widget may cost you speed and leave the lead hanging. A tap-to-call button might serve that visitor better.

Look at your own numbers. How many chats from ad visitors turned into booked jobs last month? If the answer is close to zero, try the ad page without chat for a few weeks and compare lead counts. If chat brings real jobs, keep it and load it later. For urgent trades, see plumbing landing pages.

3. Keep one chat tool

• One chat widget per page. Two bubbles means two apps loading.
• Remove chat tools left over from old trials.
• If your CRM has its own chat, decide which one your team actually answers.

Check the page before and after

The dataset shows averages, not your page. Scan the page as it is, change how chat loads, and scan again.

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