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Didomi cookie banner: speed and features

In our tests with its Nuxt integration, Didomi showed its cookie banner in a median 472 ms on desktop. It added no measurable delay to the main content. Accept responded in 16 ms and Reject in under 16 ms. It held trackers back in all 4 consent checks.

On an emulated mid-tier phone, the banner took 3.97 s. Per vendor docs, Didomi supports IAB TCF, IAB GPP, Google Consent Mode v2, Google CMP certification and Global Privacy Control.

Version tested
Hosted
Vendor
Didomi
Website
didomi.io (opens in a new tab)

Results for

Framework

How fast is Didomi’s cookie banner?

On Nuxt. We measured other CMPs on Next.js only, so this comparison uses Didomi’s other integrations.

How fast does the banner appear?

472 ms
Moderate

Median of 15 visits.

6th fastest of 6 Didomi integrations. Field median 457 ms. Didomi: 472 ms.
All 6 integrations, best first
  1. Astro433 ms
  2. TanStack Start447 ms
  3. Script tag457 ms
  4. React458 ms
  5. Next.js466 ms
  6. Nuxt472 ms

Does it slow the page down?

No measurable delay95% interval −8 ms to 20 ms
None

Main content painted as fast as on the same page without a consent manager.

No measurable delay, like 5 of the other 5 Didomi integrations. Field median 2 ms. Didomi: 4 ms.
All 6 integrations, best first
  1. Next.js−4 ms
  2. TanStack Start−4 ms
  3. Script tag0 ms
  4. Nuxt4 ms
  5. React4 ms
  6. Astro12 ms

How fast does a click respond?

16 msOne visit measured
Fast

Reject responded in under 16 ms. Under 200 ms feels instant.

Joint fastest of 6 Didomi integrations. Field median 16 ms. Didomi: 16 ms.
All 6 integrations, best first
  1. Next.js16 ms
  2. Nuxt16 ms
  3. Astro16 ms
  4. TanStack Start16 ms
  5. React16 ms
  6. Script tag16 ms

Does it block trackers until consent?

4 of 4consent checks passed
Blocked

No tracker ran and the page set no cookie before the visitor chose.

All 6 Didomi integrations passed every check. Field median 100%. Didomi: 100%.
All 6 integrations, best first
  1. Next.js100%
  2. Nuxt100%
  3. Astro100%
  4. TanStack Start100%
  5. React100%
  6. Script tag100%

Which standards and features does Didomi support?

Each status comes from Didomi’s documentation. CookieBench does not test these features unless a line says so.

  • Verified by test
  • Per vendor docs
  • Partial
  • Not supported
  • Unknown

Which frameworks does Didomi support?

First-party SDKs
React
Script tag
Supported
Measured in this run
Script tag, React, Next.js, Nuxt, Astro and TanStack Start

Support per Didomi’s documentation.

Didomi’s results by framework, desktop

Each row is a separate app. We measured each one against the same app without a consent manager. The rows compare integrations, not frameworks.

Didomi results by framework on the desktop profile: banner time, page delay, click response and tracker blocking
FrameworkBanner appearsPage slowed byClick responds inTrackers blocked
Script tag
457 msModerate
No measurable delay95% interval −8 ms to 24 msNone
Under 16 msOne visit measuredFast
4 of 4 passed
React
458 msModerate
No measurable delay95% interval −12 ms to 20 msNone
Under 16 msOne visit measuredFast
4 of 4 passed
Next.jsShared with every CMP
466 msModerate
No measurable delay95% interval −16 ms to 12 msNone
16 msOne visit measuredFast
4 of 4 passed
NuxtShown above
472 msModerate
No measurable delay95% interval −8 ms to 20 msNone
16 msOne visit measuredFast
4 of 4 passed
Astro
433 msModerate
No measurable delay95% interval 0 ms to 40 msNone
16 msOne visit measuredFast
4 of 4 passed
TanStack Start
447 msModerate
No measurable delay95% interval −20 ms to 20 msNone
16 msOne visit measuredFast
4 of 4 passed

When does Didomi load, and what does it cost the page?

Lab detail for engineers. All Core Web Vitals are here. The summary leaves some of them out.

When does Didomi start loading?

The banner was visible at 472 ms. The published results do not show when Didomi started to load.

Didomi load timeline, Desktop, Nuxt: milliseconds from navigation
EventTime from navigation
First byte (TTFB)6 ms
First paint (FCP)56 ms
Largest paint (LCP)112 ms
Banner visible472 ms
CMP requested
CMP loaded
Consent state known

How do page vitals compare with no consent manager?

Each row shows the value on the page with the consent manager. It also shows how far the value moved from the same page without one.

Didomi page vitals, Desktop, Nuxt, with the difference from a page without a consent manager
MeasureWith DidomiDifference
TTFBTime to first byte6 msNo measurable difference95% interval −1 ms to 3 ms
FCPFirst Contentful Paint56 msNo measurable difference95% interval −24 ms to 24 ms
LCPLargest Contentful Paint112 msNo measurable difference95% interval −8 ms to 20 ms
CLSCumulative Layout Shift0.00No measurable difference95% interval: 0.00
Primary content paintThe page’s main content, not the banner112 msNo measurable difference95% interval −8 ms to 20 ms

What was the largest element on screen?

LCP times the largest element on screen. If that is the banner, LCP measures the banner instead of the page.

There is no LCP attribution for this profile and framework.

What happens after a visitor clicks Accept?

The screen responded to Accept in 16 ms.

Didomi after Accept, Desktop, Nuxt: milliseconds from the click
EventTime from the click
Screen responds16 ms
Banner gone
Consent applied
Analytics active

How much does it download?

Initial transfer happens before the page settles. Deferred transfer comes after.

Didomi network use during the first load, Desktop, Nuxt
MeasureWith DidomiDifference
Initial transferBytes before the page settles806 KB+253 KB95% interval: 253 KB
Deferred transferBytes loaded laterNot compared
RequestsAll requests15+6No interval reported
Third-party requestsRequests to other hosts6+6No interval reported

Does it block the main thread?

Long tasks are stretches over 50 ms when the page cannot respond to taps or keys.

Didomi long-task time during load, Desktop, Nuxt
MeasureWith DidomiDifference
Long-task timeBlocking time during load59 ms+59 msNo interval reported

What do returning visitors see?

A visitor who accepted on an earlier visit comes back. We check that the banner stays hidden.

Banner stayed hidden
Consent state known at

What was tested?

Analysis
matrix-2026-10-11
Issues
None recorded in this run

Questions about Didomi

Answers use both test profiles.

On desktop, it appeared in a median 466 ms, against 471 ms for the median of the 10 CMPs measured. On an emulated mid-tier phone, it appeared in a median 4.41 s, against 2.71 s for the median of the 10 CMPs measured.