Cookie Banner Injector Worker

GDPR-Compliant Cookie Consent on Any Site Without Touching the Code

A Cloudflare Worker that uses Cloudflare's HTMLRewriter API to inject a fully styled, configurable cookie consent banner into every HTML response from your origin. Works on any site — no framework, no JavaScript bundle changes required.

What's Included

• Cloudflare Worker using Cloudflare's HTMLRewriter for streaming HTML injection
• Pre-built cookie consent banner with Accept/Decline buttons
• Configurable banner text, button labels, and link to your privacy policy
• CSS-in-JS injection — no separate stylesheet files or CDN dependencies
• Consent stored in a cookie — banner hidden on return visits
• Optional GTM / analytics activation on consent (configurable)
• README with customization and styling guide

How It Works

The Worker intercepts HTML responses and uses HTMLRewriter's streaming transformer to append the banner markup and inline styles to the <body> element before bytes reach the browser. On first visit, the banner appears. When the user consents or declines, the choice is saved in a cookie and the Worker skips injection on all subsequent requests from that browser.

What You Get

• Drop-in GDPR compliance on any origin without deploying code changes
• Works on static sites, legacy apps, and dynamically rendered pages
• Configurable colours and copy to match your brand
• No third-party consent management platform (CMP) subscription required
• Streaming injection — no visible layout shift or FOUC

Requirements

• Cloudflare account (free tier works)
• Domain on Cloudflare DNS
• Wrangler CLI installed (npm install -g wrangler)