How to Detect What CMS a Website Uses (And Why You'd Want To)
Ever looked at a really cool website and thought, "I wonder what they built this with?" Yeah, me too. All the time, actually. It's kind of become an obsession at this point – my girlfriend makes fun of me for it. But here's the thing: knowing what CMS or technology a website uses can tell you a lot. Whether you're a developer looking for inspiration, a business owner checking out competitors, or just curious by nature, CMS detection is actually a super useful skill.
Let me show you how to do it.
Why Would Anyone Want to Detect a CMS Anyway?
Before we dive into the how, let's talk about the why. Because honestly, when I first started doing this, people thought I was being weird. "Why do you care what platform that website uses?" they'd ask. Well, turns out there are actually a bunch of good reasons.
Competitive Research
If you're running a business, wouldn't you want to know what your competitors are using? I mean, if your competitor's e-commerce site is crushing it and they're using Shopify, that's useful information, right? Maybe Shopify has features that would help your business too.
I had a client once who was struggling with their outdated custom-built platform. We looked at their three biggest competitors, found out they were all on Shopify, did some research, and discovered why. Made the decision to migrate a lot easier when we could show them concrete examples of similar businesses succeeding on that platform.
Developer Research
As a developer, this is like looking under the hood of a car. You see a site with a really cool feature, you check what CMS they're using, and boom – you know where to look for plugins or code examples. It's basically legal spying, and it's totally normal in the dev community.
I've learned about so many great WordPress plugins just by detecting what successful sites are using. It's like having a cheat code for finding good tools.
Security Research
Okay, this one gets into grey area territory, so I'm going to be careful here. But security researchers often need to know what CMS a site uses to identify potential vulnerabilities. This is legitimate security research – not hacking. Big difference.
If you're a security professional, knowing a site runs on WordPress 4.2 (which is ancient and vulnerable) is important information. You can reach out to the site owner and let them know they need to update.
Just Plain Curiosity
Sometimes you just want to know, you know? There's something satisfying about figuring it out. It's like a little puzzle. Plus, you start to develop an eye for it. I can usually tell if something's WordPress just by looking at it for a few seconds. My friends think it's either impressive or sad. I haven't decided which.
The Manual Methods: Using Your Eyes and Browser
Let's start with the basics – the stuff you can do without any fancy tools. These methods work surprisingly often.
Method 1: Look at the Source Code
This is old school, but it works. Here's what you do:
1. Go to the website
2. Right-click anywhere and select "View Page Source" (or press Ctrl+U on Windows, Cmd+Option+U on Mac)
3. Hit Ctrl+F (or Cmd+F) to search
4. Look for telltale signs
What kind of signs? Well, let me show you some examples:
For WordPress:
Search for "wp-content", "wp-includes", or "wordpress"
You'll usually find something like:
See that "wp-content"? Dead giveaway. That's WordPress.
For Joomla:
Search for "joomla" or "/components/com_"
For Drupal:
Search for "drupal" or "sites/all"
For Shopify:
Search for "shopify" or "cdn.shopify.com"
I remember when I first learned this technique, I felt like a hacker from a movie. In reality, it's about as sophisticated as reading the label on someone's shirt, but it feels cooler.
Method 2: Check the Meta Generator Tag
A lot of CMS platforms are nice enough to basically introduce themselves in the source code. They include something called a meta generator tag that says "Hey, I was built with [platform name]!"
Look for something like this in the source code:
Not all sites have this (some people remove it for security reasons), but when they do, it makes your life really easy.
Pro tip: Some sites try to be sneaky and remove these tags. That's fine – we have other methods.
Method 3: Look at the URL Structure
Different CMS platforms have different ways of organizing their URLs. After you've been doing this a while, you can often tell just by looking at the address bar.
WordPress:
- /wp-admin/ (the admin login)
- /wp-content/
- /wp-json/ (their REST API)
Shopify:
- /collections/
- /products/
- Often has "myshopify.com" in the URL or page source
Wix:
- Usually has super long URLs with weird strings of letters and numbers
- The source code is often completely obfuscated (unreadable)
Blogger/Blogspot:
- .blogspot.com in the URL
- Even if they have a custom domain, you'll see Blogger references in the source
I actually figured out a competitor was using Shopify just because I noticed their URL structure looked familiar. Saved me hours of investigation.
Method 4: Check HTTP Headers
This one's a bit more technical, but still pretty easy. HTTP headers are like little notes that websites send with every page request. Sometimes they include information about what's running on the server.
Here's how to check:
1. Open your browser's Developer Tools (F12 on most browsers)
2. Go to the "Network" tab
3. Reload the page
4. Click on the first request (usually the HTML document)
5. Look at the "Headers" section
Look for headers like:
- X-Powered-By: PHP/7.4 (might indicate WordPress or other PHP CMS)
- X-Generator: Drupal 9
- X-Shopify-Stage: production
Sometimes the headers give it away immediately. Other times, they're more subtle. But it's always worth checking.
The Easy Way: Online CMS Detection Tools
Okay, so manual methods are cool and all, but honestly? Most of the time I just use online tools. Why make things harder than they need to be?
There are a bunch of free tools that will detect CMS for you. You just enter the URL and they tell you what's running. It's like magic, except it's just clever programming.
Popular CMS Detection Tools:
WhatCMS.org
This is probably the most popular one. Simple interface – you enter a URL, hit enter, done. It checks for like 400+ different CMS platforms. I use this one constantly.
BuiltWith.com
This is more comprehensive. It doesn't just tell you the CMS – it tells you everything. What analytics they're using, what advertising platforms, what CDN, everything. It's almost too much information sometimes, but really useful for deep competitive research.
Wappalyzer
This is a browser extension (Chrome and Firefox). Once you install it, it shows you the technology stack of whatever site you're visiting, right in your browser toolbar. Super convenient. I have this installed and use it all the time.
WP Theme Detector
Specifically for WordPress sites. Not only tells you it's WordPress, but also tells you what theme and plugins they're using. As a WordPress developer, this tool has saved me so many hours.
Here's a real story: I was redesigning a client's website, and they loved the layout of a competitor's site. Used WP Theme Detector, found out the theme they were using, bought it for $60, and had a head start on the project. Saved probably 20 hours of design work.
The Technical Way: Using Command Line Tools
Alright, now we're getting into the nerdy stuff. If you're a developer or just want to feel like one, here are some command-line methods.
Using cURL
cURL is a command-line tool for making HTTP requests. You can use it to check headers:
curl -I https://example.com
This will show you the HTTP headers, which might reveal the CMS.
Using WhatWeb
WhatWeb is a command-line tool specifically for website fingerprinting. Install it and run:
whatweb https://example.com
It'll give you a detailed breakdown of what technologies the site uses.
I'll be honest – I don't use command-line tools that often for this anymore. They're powerful, but for most purposes, the online tools are faster and easier. But if you're automating checks for lots of sites, command-line tools are the way to go.
Advanced Techniques: The Detective Work
Sometimes sites really don't want you to know what CMS they're using. They've removed all the obvious signs. That's when you have to get creative.
Check the Robots.txt File
Go to: https://example.com/robots.txt
This file tells search engines what to index. It often reveals CMS-specific directories:
User-agent: *
Disallow: /wp-admin/
Disallow: /wp-includes/
Oh hey, looks like WordPress!
Look for Default Files
Try accessing common default files:
- /wp-login.php (WordPress)
- /administrator/ (Joomla)
- /user/login (Drupal)
If these load, you know what CMS they're using, even if they've hidden other signs.
Check the Comments in Source Code
Developers often leave comments in their code. Search the source for HTML comments (they look like ). You might find gems like:
Examine the JavaScript Files
Different CMS platforms use different JavaScript libraries and structure them differently. Look at what JS files are being loaded. WordPress sites often load jQuery in the header. Shopify sites have Shopify-specific JavaScript files.
Use Multiple Tools
Sometimes one tool misses what another catches. I usually check with at least 2-3 different tools if I'm not getting clear results. It's like getting a second opinion.
Common CMS Signatures: A Quick Reference
Here's a cheat sheet I keep handy. These are the most common telltale signs for popular platforms:
WordPress:
- /wp-content/ in URLs or source
- wp-json API endpoints
- /wp-admin/ login page
- "generator" meta tag with WordPress
Shopify:
- cdn.shopify.com in source
- "myshopify.com" references
- Shopify.theme in JavaScript
- /collections/, /products/ URLs
Wix:
- Extremely long, generated URLs
- "wixstatic.com" in source
- Obfuscated JavaScript
- Very clean source code (too clean)
Joomla:
- /components/com_ in URLs
- "generator" meta tag with Joomla
- /media/jui/ directory
- Joomla-specific JS files
Drupal:
- /sites/all/ or /sites/default/
- "generator" meta tag with Drupal
- Drupal.settings in JavaScript
- /core/misc/ directory
Squarespace:
- squarespace.com references
- Very specific URL structure
- sqsp.com in source
Blogger:
- blogspot.com domain or references
- blogger.com in source
- Specific Blogger widgets and code
The Ethics of CMS Detection
Let's have a quick chat about ethics, because this is important. CMS detection itself is completely legal and ethical. You're just looking at publicly available information. It's no different than looking at a store's window display to see what products they carry.
However, what you do with that information matters. Here's my personal code:
Ethical:
- Researching competitors
- Finding inspiration
- Security research with good intentions
- Learning and education
Not Ethical:
- Using the information to hack or attack sites
- Stealing exact designs or code
- Exploiting known vulnerabilities without disclosure
If you're a security researcher and you find a vulnerability, do the right thing: notify the site owner privately, give them time to fix it, then disclose publicly if needed. That's responsible disclosure.
Real-World Use Cases
Let me share some stories about when CMS detection has actually been useful:
Use Case 1: The Shopify Migration
I had a client who wanted to move their struggling online store to a better platform. They asked me what I recommended. Instead of just giving them my opinion, we analyzed their top 10 competitors. Eight of them were on Shopify, one was on WooCommerce, and one was on a custom platform.
We dug deeper into the Shopify ones and found they were all doing well. Made the recommendation easy: migrate to Shopify. The client loved that we had data to back up our recommendation.
Use Case 2: The Theme Discovery
A designer friend of mine found a WordPress site with a layout she loved. Used a theme detector, found out it was a premium theme called Divi. She bought it, learned it, and now it's her go-to theme for client projects. She's built like 30 sites with it now.
Use Case 3: The Security Alert
I was checking out random websites one day (yeah, I do this for fun – I know, I need a hobby), and found a site that was clearly hacked. It was showing spam content. I detected it was WordPress, checked the version (badly outdated), and sent the owner a friendly email letting them know. They were grateful and got it fixed.
Use Case 4: The Plugin Find
Saw a really cool image gallery on a photography site. Detected it was WordPress, used a plugin detector, found out they were using a specific gallery plugin. Bought the plugin for $30, saved myself hours of trying to code something similar.
Troubleshooting: When Detection Doesn't Work
Sometimes you can't figure out what CMS a site uses. Here's why that might happen:
1. It's Not a CMS
Some sites are custom-built from scratch. No CMS at all. These can be tough to identify because there are no standard patterns.
2. They've Hidden the Signs
Some sites deliberately remove CMS signatures for security or branding reasons. It's like removing the logo from your car.
3. It's a Headless CMS
These are tricky because the CMS is completely separated from the frontend. The frontend might be built with React or Vue.js, and the CMS is just feeding data in the background.
4. Multiple Technologies
Some sites use hybrid approaches. Maybe WordPress for the blog but custom code for the main site. Or Shopify for the store but WordPress for the blog.
5. Heavy Customization
If a site has been customized enough, it might not look like any standard CMS anymore.
When this happens, I usually:
- Try multiple detection tools
- Look more carefully at the source code
- Check what the site footer says (sometimes they credit the builder)
- Google the company name + "website platform" to see if they've mentioned it publicly
The Future of CMS Detection
This field is constantly evolving. Here's what I think we'll see:
More Headless CMS
As these become more popular, detection will get trickier. We'll need new techniques that focus on API patterns and data structures.
Better Obfuscation
Sites will get better at hiding their technology stack. Already seeing this with services that promise to "cloak" your CMS.
AI-Powered Detection
We'll probably see AI tools that can identify CMS platforms based on subtle patterns and behaviors, not just obvious signs.
Browser Extensions Get Smarter
Tools like Wappalyzer will get even better at identifying technologies, including detecting versions, plugins, and themes.
My Personal CMS Detection Workflow
Since people ask me this all the time, here's exactly what I do when I need to identify a CMS:
1. Quick Visual Scan: Can I tell just by looking? (Works for Wix, often for WordPress)
2. Check with Wappalyzer: I have the extension installed, so this takes zero effort
3. Use WhatCMS.org: If Wappalyzer doesn't give me what I need
4. Manual Source Code Check: If the tools aren't conclusive
5. Try Common URLs: Access /wp-admin/, /administrator/, etc.
6. Use BuiltWith: If I need deep information
7. Google It: Sometimes the company has mentioned their platform in a blog post or case study
This workflow takes me maybe 2-3 minutes and works 95% of the time.
Tips from Someone Who Does This Way Too Much
Here are some random tips I've picked up:
- Install Wappalyzer. Seriously. It's free and saves so much time.
- Don't trust one tool completely. Cross-reference when it matters.
- The absence of evidence isn't evidence of absence. Just because you can't detect a CMS doesn't mean there isn't one.
- Learn to recognize common design patterns. Wix sites have a certain "feel," as do Squarespace sites.
- Check the site footer. Sometimes they have "Powered by [Platform]" links.
- Look at the URL structure. It's often the quickest way to identify a CMS.
- Join developer communities. You'll learn tricks from other people who do this.
- Practice on sites you know the platform for. It helps train your eye.
Wrapping Up
CMS detection is one of those skills that seems mysterious until you learn it, and then it seems obvious. It's like learning to ride a bike – seems impossible, then suddenly it's second nature.
Whether you're using it for competitive research, development work, or just satisfying curiosity, it's a genuinely useful skill in today's web-focused world. And the best part? It's actually kind of fun once you get into it.
So next time you see a cool website, don't just admire it – figure out what makes it tick. You might learn something useful. And hey, maybe you'll develop the same slightly-annoying habit I have of automatically detecting every website you visit. My girlfriend says it's a problem, but I think it's just being thorough.
Now if you'll excuse me, I need to check what CMS my favorite restaurant's website is using...
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What's your favorite CMS detection tool? Or do you have any cool detection stories to share? Drop a comment – I'd love to hear them!