Do OneTrust and Didomi both support IAB TCF?

Both document it. Statuses come from vendor docs.

Do OneTrust and Didomi block trackers before consent?

Both held trackers back in every check. Each check loads the page. Then it looks for trackers that ran, cookies that the page set or data that left the page before the visitor chose.

OneTrust vs Didomi: cookie banner speed and features compared

Results forFramework

On desktop, Didomi showed its banner sooner (498 ms vs 672 ms) but transferred 253 KB more than a page without a consent manager, against 211 KB for OneTrust. Neither added a measurable delay to the main content on desktop. On emulated mobile, Didomi added 1.29 s before the main content appeared and OneTrust 692 ms. Didomi’s was the largest delay on Next.js in this run.

OneTrustOneTrust

OneTrust Tested: Hosted
All OneTrust results

DidomiDidomi

Didomi Tested: Hosted
All Didomi results

Which is faster, OneTrust or Didomi?

Shorter bars are better. The exception is tracker blocking, where the bar shows the share of checks passed.

OneTrust and Didomi on the desktop profile, Next.js 16
Question	OneTrust	Didomi	Difference
Banner appearsTime from navigation until the banner is visible on screen. Lower is better.	629 msModerate	466 msModerate	Didomi’s banner appeared 164 ms sooner.
Page slowed byExtra time before the main content paints (LCP), compared with the same page without a consent manager.	No measurable delay95% interval −20 ms to 20 msNone	No measurable delay95% interval −16 ms to 12 msNone	Neither added a measurable delay.
Click responds inTime from pressing Accept until the screen updates. Under 200 ms feels instant.	24 msOne visit measuredFast	16 msOne visit measuredFast	About the same. They are less than 16 ms apart.
Blocks trackersChecks that no tracker runs, the page sets no cookie and no data leaves the page before the visitor chooses.	4 of 4 checks passedBlocked	4 of 4 checks passedBlocked	Both held trackers back in every check.
Adds to pageExtra data transferred during the first load, compared with the same page without a consent manager.	+211 KB95% interval: 211 KBModerate	+253 KB95% interval: 253 KBHeavy	OneTrust added 42 KB less to the first load.

“About the same” means that the two results fall within each other’s spread. We measure both against the same page without a consent manager. We do not publish a direct head-to-head interval yet.

Page vitals and load times

Lab detail for engineers. All values are medians on the desktop profile. Both CMPs ran on Next.js 16.

Page vitalsChange against the same page without a consent manager.
Metric	OneTrust	Didomi
TTFB	No measurable delaypage 6 ms	No measurable delaypage 6 ms
FCP	No measurable delaypage 60 ms	No measurable delaypage 68 ms
LCP	No measurable delaypage 124 ms	No measurable delaypage 120 ms
CLS	No measurable shiftpage 0.00	No measurable shiftpage 0.00

Load timesMilliseconds from navigation.
Metric	OneTrust	Didomi
CMP script requested
CMP script loaded
Consent state known
Banner visible	629 ms	466 ms

After AcceptMilliseconds from the click.
Metric	OneTrust	Didomi
Screen responds	24 ms	16 ms
Banner gone
Consent applied
Analytics active

Which features differ between OneTrust and Didomi?

Statuses come from each vendor’s documentation. Each status links to its source.

Verified by test
Per vendor docs
Partial
Not supported
Unknown

Features that differ between OneTrust and Didomi, from vendor docs
Feature	OneTrustOneTrust	DidomiDidomi
Only Didomi · 1
First-party SDKsFrameworks	Script tag only (vendor documentation, opens in a new tab)	React (vendor documentation, opens in a new tab)
Not confirmed for one side · 1
TypeScript typesDeveloper	Unknown	React SDK only (vendor documentation, opens in a new tab)

Same on both · 15

Should you choose OneTrust or Didomi?

The CookieBench maintainers wrote these lists from the results and features above.

Choose OneTrust if

Your privacy team already runs other OneTrust modules
Mobile load time on slow phones is a priority

Choose Didomi if

You want a dedicated consent and preference platform
Desktop banner speed matters more than page weight

What was tested?

Deployment: Both ran from their vendor-hosted services. Network distance to each vendor is part of the result.

How we test: methodology cookiebench-v3.2.4

Questions about OneTrust and Didomi

Answers come from the benchmark run and from each vendor’s documentation.

Report a correction

On the desktop profile, Didomi’s banner appeared in a median 466 ms and OneTrust’s in 629 ms. Neither added a measurable delay.

All comparisons

Feature	OneTrustOneTrust	DidomiDidomi
IAB TCFStandards	TCF v2.2 and v2.3 (vendor documentation, opens in a new tab)	TCF v2.2 (vendor documentation, opens in a new tab)
IAB GPPStandards	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Google Consent Mode v2Standards	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Google-certified CMPStandards	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Global Privacy ControlStandards	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Geo-targeted bannersCompliance	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Script blockingCompliance	Per vendor docs (vendor documentation, opens in a new tab)	Tag-based (vendor documentation, opens in a new tab)
Consent recordsCompliance	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Cookie scanningCompliance	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Open sourceDeveloper	Proprietary (vendor documentation, opens in a new tab)	Proprietary (vendor documentation, opens in a new tab)
Self-hostableDeveloper	Script only; hosted backend (vendor documentation, opens in a new tab)	Assets through your domain (vendor documentation, opens in a new tab)
Headless UIDeveloper	Mobile and CTV only (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
Free tierPricing	Quote-based pricing (vendor documentation, opens in a new tab)	Contact sales (vendor documentation, opens in a new tab)
Script tagFrameworks	Per vendor docs (vendor documentation, opens in a new tab)	Per vendor docs (vendor documentation, opens in a new tab)
First-party SDKsNext.js, Vue, Nuxt, Svelte, SvelteKit, Astro, TanStack Start	Script tag only (vendor documentation, opens in a new tab)	Script tag only (vendor documentation, opens in a new tab)