# c15t vs CookieYes: cookie banner speed and features

On desktop, c15t showed its banner sooner, in a median 60 ms against 387 ms for CookieYes. Their delay to the main content was about the same. The 95% intervals overlap. Neither leaked a tracker in the checks that ran. We could not run 1 of 4 checks for CookieYes. Per vendor docs, only c15t offers open-source code. Per vendor docs, only CookieYes offers a Google-certified CMP.

We measured both in the same run, in a Next.js app. We measured each against the same page without a consent manager. They also share Script tag, React, Nuxt, Astro, TanStack Start integrations.

## Which is faster on desktop?

Desktop profile: 1365 × 768 · No CPU slowdown · 12.5 MB/s, no added latency.

| Question | c15t | CookieYes | Difference |
| --- | --- | --- | --- |
| How fast does the banner appear? | 60 ms | 387 ms | c15t’s banner appeared 327 ms sooner. |
| Does it slow the page down? | +16 ms (95% interval 8 ms to 40 ms) | No measurable change | About the same. The 95% intervals overlap. |
| How fast does a click respond? | 16 ms | 16 ms | About the same. They are less than 16 ms apart. |
| Does it block trackers until consent? | 4 of 4 checks passed | 3 of 4 checks passed. We could not check the other 1 | Neither leaked a tracker in the checks that ran. We could not run 1 of 4 checks for CookieYes. |
| How much does it add to the page? | +112 KB (95% interval: 112 KB) | +31 KB (95% interval: 31 KB) | CookieYes added 81 KB less to the first load. |

## Which is faster on mobile?

Mobile (emulated) profile: 390 × 844, DPR 3 · Mid-tier phone CPU (4× slowdown) · 200 KB/s, 150 ms latency.

On emulated mobile, c15t showed its banner sooner, in a median 240 ms against 2.42 s for CookieYes. CookieYes delayed the main content 232 ms less. Neither leaked a tracker in the checks that ran. We could not run 1 of 4 checks for CookieYes. Per vendor docs, only c15t offers open-source code. Per vendor docs, only CookieYes offers a Google-certified CMP.

| Question | c15t | CookieYes | Difference |
| --- | --- | --- | --- |
| How fast does the banner appear? | 240 ms | 2.42 s | c15t’s banner appeared 2.18 s sooner. |
| Does it slow the page down? | +408 ms (95% interval 396 ms to 420 ms) | +176 ms (95% interval 148 ms to 212 ms) | CookieYes delayed the main content 232 ms less. |
| How fast does a click respond? | 32 ms | 24 ms | About the same. They are less than 16 ms apart. |
| Does it block trackers until consent? | 4 of 4 checks passed | 3 of 4 checks passed. We could not check the other 1 | Neither leaked a tracker in the checks that ran. We could not run 1 of 4 checks for CookieYes. |
| How much does it add to the page? | +112 KB (95% interval: 112 KB) | +31 KB (95% interval: 31 KB) | CookieYes added 81 KB less to the first load. |

## Which features differ?

| Feature | c15t | CookieYes |
| --- | --- | --- |
| IAB TCF | Per vendor docs | Per vendor docs (Pro and Ultimate plans) |
| IAB GPP | Per vendor docs (GPP 1.1) | Unknown |
| Google Consent Mode v2 | Per vendor docs | Per vendor docs |
| Google-certified CMP | Not supported (Not on Google’s list) | Per vendor docs |
| Global Privacy Control | Per vendor docs | Per vendor docs (Pro and Ultimate plans) |
| Geo-targeted banners | Per vendor docs | Per vendor docs (Pro and Ultimate plans) |
| Script blocking | Per vendor docs | Per vendor docs |
| Consent records | Per vendor docs (With a backend) | Per vendor docs |
| Cookie scanning | Per vendor docs (Via Inth Website Audit) | Per vendor docs |
| Open source | Per vendor docs (Apache-2.0) | Not supported (Proprietary) |
| Self-hostable | Per vendor docs | Unknown |
| Headless UI | Per vendor docs | Unknown |
| TypeScript types | Per vendor docs | Unknown |
| Free tier | Per vendor docs (Open source; hosted free plan) | Per vendor docs (5,000 pageviews a month) |
| Script tag | Per vendor docs | Per vendor docs |
| React SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| Next.js SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| Vue SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| Nuxt SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| Svelte SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| SvelteKit SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| Astro SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |
| TanStack Start SDK | Per vendor docs (First-party SDK) | Not supported (Script tag only) |

## Which should you choose?

### Choose c15t if

- You want open-source code
- You want a first-party SDK for React, Next.js, Vue, Nuxt, Svelte, SvelteKit, Astro and TanStack Start
- A fast banner matters to you: c15t’s banner appeared 327 ms sooner

### Choose CookieYes if

- You need a Google-certified CMP
- Page weight matters to you: CookieYes added 81 KB less to the first load

## Questions about this pair

### Is CookieYes slower than c15t?

On the desktop profile, c15t’s banner appeared in a median 60 ms and CookieYes’ in 387 ms. Their delay to the main content was about the same. The 95% intervals overlap.

### Does c15t support Google-certified CMP like CookieYes?

No, per vendor docs. CookieYes documents Google-certified CMP support. c15t does not.

### Do c15t and CookieYes block trackers before consent?

Neither leaked a tracker in the checks that ran. We could not run 1 of 4 checks for CookieYes. 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.

## Related comparisons

- [c15t vs OneTrust](https://cookiebench.com/compare/c15t-vs-onetrust.md)
- [c15t vs Usercentrics](https://cookiebench.com/compare/c15t-vs-usercentrics.md)
- [c15t vs Didomi](https://cookiebench.com/compare/c15t-vs-didomi.md)
- [c15t vs Osano](https://cookiebench.com/compare/c15t-vs-osano.md)
- [c15t vs iubenda](https://cookiebench.com/compare/c15t-vs-iubenda.md)
- [c15t vs Ketch](https://cookiebench.com/compare/c15t-vs-ketch.md)

Methodology [cookiebench-v3.2.4](https://cookiebench.com/methodology). inth, the team behind c15t, maintains CookieBench. c15t is one of the consent managers we measure ([disclosure](https://cookiebench.com/methodology)). Feature support comes from vendor documentation unless a row says "Verified by test".