Core Web Vitals and website speed optimisation in India
Ranked by return per hour of work, not by what is easiest to sell.
Core Web Vitals measure loading (LCP, target under 2.5s), responsiveness (INP, under 200ms) and layout stability (CLS, under 0.1). On Indian business sites the biggest wins are almost always image weight, third-party scripts and render-blocking fonts — usually two to four seconds recoverable in under a week of work.
Key takeaways
- Measure field data in Search Console, not lab scores — real users on real phones are the ones being scored.
- Images and third-party tags are responsible for most of the damage on the average Indian business site.
- INP replaced FID in 2024 and punishes heavy JavaScript on interaction, which is where page builders lose.
- Speed is a conversion lever before it is a ranking lever; treat it as revenue work.
Most Indian traffic is a mid-range Android phone on a congested network. That is the device your site is being graded on, by Google and by the visitor, and it is almost never the device your site was tested on.
The three metrics, in plain terms
| Metric | What it measures | Target |
|---|---|---|
| LCP | How long until the main content appears | Under 2.5s |
| INP | How quickly the page responds when tapped | Under 200ms |
| CLS | How much the layout jumps while loading | Under 0.1 |
Search Console reports these from real Chrome users, which is the number that counts. A Lighthouse run on your laptop is a diagnostic, not a grade.
The fixes, in order of return
1. Images
On the average Indian business site, images are half the page weight and the LCP element is one of them. Serving modern formats at the correct size for the device, with width and height set so nothing shifts, is routinely worth a second or more. It is also the cheapest fix on this list.
2. Third-party scripts
Chat widgets, heat maps, three analytics tools and two pixels, all loading before your content. Audit every tag, delete the ones nobody has opened a report from in six months, and defer the rest. Marketing teams resist this until they see the before-and-after conversion numbers.
3. Fonts
A render-blocking web font holds your text hostage. Self-host, preload the one weight above the fold, and set a fallback so text is readable while the font arrives.
4. JavaScript on interaction
INP is where page builders and plugin-heavy stacks lose badly: the tap registers, then a hundred milliseconds of someone else's code runs before anything visible happens. The fix is structural — ship less JavaScript — which is why it usually arrives with a rebuild rather than a tune-up.
How we run a speed engagement
- 01Pull 28 days of field data from Search Console and CrUX, per template rather than per page.
- 02Profile the worst template on a throttled mobile connection and identify the LCP element.
- 03Ship the image, font and tag fixes first — usually a week, usually most of the gain.
- 04Re-measure field data after 28 days, because that is the window Google reports on.
- 05Set a performance budget in CI so the gain does not quietly erode over the next two quarters.
If the site is on a stack where the structural fixes are not possible, we say so and price a rebuild instead of selling six months of optimisation retainers against a ceiling.