✨ Open Source — MIT Licensed

Inject JS & CSS into
any website you visit

Injectify is a lightweight Chrome Extension that lets you run custom JavaScript, apply CSS tweaks, and load CDN libraries on any site — controlled by flexible, per-domain rules.

MV3 Manifest Version 3
JS+CSS + CDN Support
Rules per domain
MIT Open Source

Everything you need to customise the web

Injectify gives you fine-grained control over every page you visit — with zero configuration headaches.

JavaScript Injection

Run custom scripts on any page. Automate tasks, modify DOM, interact with page APIs.

🎨

CSS Injection

Apply custom stylesheets instantly. Dark mode, layout tweaks, branding overrides — anything.

📦

CDN Script Loading

Load jQuery, lodash, Vue, or any CDN library before your custom JS runs.

🎯

Flexible URL Patterns

Match by exact domain, wildcard subdomain (*.example.com), glob, or full RegExp.

🔀

Multiple Rules

Create unlimited rules per site. Toggle each on/off independently without deleting them.

💾

Import & Export

Backup your rules as JSON, share them with teammates, or restore them after reinstalling.

🔒

Secure by Design

No remote code execution. No eval(). Your scripts run only when you authorise them.

🌐

Works Everywhere

Any URL — HTTP, HTTPS, or local servers. Pin to specific domains or go truly global.

🛠️

Manifest V3 Ready

Built on Chrome's latest extension platform. Faster, more secure, future-proof.

Simple, rule-driven injection

Injectify matches the current page URL against your saved rules and applies matching ones automatically.

1

Open Options

Click the Injectify icon and go to Manage all rules to open the full dashboard.

2

Create a rule

Give it a name, set a URL pattern like github.com or * for all pages, then paste your JS and/or CSS.

3

Enable & reload

Toggle the rule on and reload the target page. Injectify injects your code automatically.

4

See results instantly

The popup shows which rules are active on the current page. Disable or edit at any time.

Example rule — GitHub dark header
// URL pattern: github.com

// CSS field:
.AppHeader { background: #0d1117 !important; }

// JavaScript field:
console.log(
  '[Injectify] Active on',
  document.title
);

// CDN field:
https://cdn.jsdelivr.net/npm/lodash@4/lodash.min.js

Clean, minimal UI

The popup and options dashboard are designed to stay out of your way.

Popup (active rules)
Options — Rules dashboard
Options — Edit rule form

Load unpacked in under a minute

Injectify is not (yet) on the Chrome Web Store, so you load it directly from the source — it takes less than 60 seconds.

1

Download the source

Clone the repo or download the ZIP from GitHub.

git clone https://github.com/
shade-solutions/Injectify.git
2

Open Chrome Extensions

Navigate to the extensions management page.

chrome://extensions
3

Enable Developer Mode

Toggle the Developer mode switch in the top-right corner.

4

Load Unpacked

Click Load unpacked and select the /extension folder from the cloned repo.

5

Pin & use

Pin Injectify to your toolbar. Click its icon on any page to see active rules.

URL pattern reference

Injectify supports several pattern syntaxes — pick the one that fits your use case.

Pattern Matches Example
* Every URL Applies to all pages
example.com Exact hostname example.com and any sub-path
*.example.com All subdomains app.example.com, api.example.com…
https://example.com/* Glob / Chrome match pattern Only HTTPS pages under that origin
/github\.com\/\w+/i JavaScript RegExp Full regex with optional flags

Help make Injectify better

Injectify is fully open-source. Found a bug? Have a feature idea? PRs and issues are always welcome.