c15t
A free, open-source cookie consent banner built for developers, so you're not stuck configuring a clunky third-party widget that slows down your site.
🔗 Visit c15t
Description
Every website needs a cookie consent banner these days, but the usual options are either a heavyweight third-party script that adds load time and looks out of place on your site, or building consent logic from scratch, which is easy to get legally wrong. c15t splits the difference: it's an open-source toolkit built specifically for developers using React, Next.js, or plain JavaScript, giving you either ready-made UI components or a headless API if you want full control over the look.
c15t (Apache 2.0 licensed) provides consent-aware script loading for analytics, ad pixels, and tag managers, with support for the IAB TCF 2.3 standard and Google Consent Mode v2. It ships framework-specific packages (@c15t/react, @c15t/nextjs, @c15t/scripts, @c15t/iab) and can run fully self-hosted, via a managed backend, or in offline mode. It has around 1,800 GitHub stars and is used on 2,100+ sites including Expo, Cal.com, and Zed. c15t is built by Inth (formerly Consent.io), a Y Combinator company also building a broader enterprise privacy governance platform.
💬 Our review
The short version: for developers who've been annoyed by clunky, slow-loading consent banner widgets from vendors like OneTrust or Cookiebot, c15t's free, open-source, code-first approach is a genuinely better developer experience — you get real components or a headless API instead of an embedded iframe.
The tradeoff versus OneTrust or Cookiebot is exactly what you'd expect from an open-source, self-hosted tool: no dedicated compliance support team, no enterprise SLA, and you (or your dev team) are responsible for getting the implementation right, even though the library handles the standards compliance (IAB TCF 2.3, Google Consent Mode) for you. Being free and self-hostable makes it a clear win for cost-conscious teams or open-source projects, and its adoption by teams like Expo and Cal.com is a reasonable trust signal. For developer-led teams comfortable integrating a library themselves who want a fast, code-native consent banner, c15t is hard to beat on price and control; larger enterprises wanting a fully managed compliance product with dedicated support are still better served by OneTrust.
📊 Global score
🤖 AI-enriched data
Self-hosted : gratuit (Apache 2.0). Backend géré (via Inth) : prix non public.
Pros
100% open-source, licence Apache 2.0
Composants prêts à l'emploi ou API headless au choix
Support IAB TCF 2.3 et Google Consent Mode v2
Utilisé par Expo, Cal.com, Zed (2100+ sites)
Cons
Nécessite une implémentation par un développeur
Pas de support entreprise dédié comme OneTrust
Prix du backend géré non public