TL;DR: No single free tool covers everything. Google PageSpeed Insights focuses on performance, GTmetrix adds waterfall diagnostics, SecurityHeaders.com checks one narrow security layer, and PageVital scores performance, security, SEO, and technology in a single scan with a unified A-to-F grade. The best approach is to understand what each tool actually measures so you pick the right one for the question you are asking.
Why Tool Choice Matters
Running a website audit with the wrong tool is like checking your car's tire pressure when the engine light is on. Each audit tool measures a specific subset of website health. If you only use a performance tool, you will miss security misconfigurations. If you only check security headers, you will miss the SEO issues that are actually costing you traffic.
This comparison covers four tools that are genuinely free — no trial limitations, no gated results, no credit card required. We will be direct about what each tool does well, where it falls short, and when you should use each one.
The Comparison at a Glance
| Feature | PageVital | Google PageSpeed Insights | GTmetrix | SecurityHeaders.com | |---------|-----------|--------------------------|----------|---------------------| | Performance scoring | ✅ Core Web Vitals + page speed | ✅ Lighthouse performance score | ✅ Performance + waterfall analysis | ❌ Not tested | | Security audit | ✅ 9 checks (SSL, headers, mixed content) | ❌ Not tested | ❌ Not tested | ✅ HTTP headers only | | SEO analysis | ✅ Meta tags, structure, indexability | ⚠️ Basic (SEO section in Lighthouse) | ❌ Not tested | ❌ Not tested | | Technology detection | ✅ CMS, frameworks, CDN, analytics | ❌ Not detected | ❌ Not detected | ❌ Not detected | | Overall grade | ✅ A-to-F composite grade | ❌ Score 0-100 (performance only) | ✅ Letter grade (performance only) | ✅ Letter grade (headers only) | | Historical tracking | ✅ Score history over time | ❌ Snapshot only | ⚠️ Paid plans only | ❌ Snapshot only | | Scan speed | ~15-30 seconds | ~10-30 seconds | ~30-60 seconds | ~2-5 seconds | | API access | ✅ REST API | ✅ PageSpeed API | ⚠️ Paid plans only | ❌ Not available | | Batch scanning | ✅ Multiple URLs | ❌ One URL at a time | ⚠️ Paid plans only | ❌ One URL at a time |
Google PageSpeed Insights: The Performance Specialist
Google PageSpeed Insights (PSI) runs a Lighthouse audit against your URL and returns a performance score from 0 to 100. It measures Core Web Vitals — Largest Contentful Paint, Cumulative Layout Shift, and Interaction to Next Paint — using both lab data (simulated) and field data (from real Chrome users via the CrUX dataset).
What PSI does well:
- Authoritative Core Web Vitals data because it is Google's own tool and uses the same data that influences rankings
- Specific, actionable suggestions for each performance issue (unused JavaScript, render-blocking resources, image optimization)
- Field data from real users when your site has enough traffic in the Chrome User Experience Report
Where PSI falls short:
- Performance only. It tells you nothing about security configuration, SEO completeness, or what technology your site runs on.
- No historical tracking. Each scan is a snapshot — you cannot see trends over time without running scans manually and recording results.
- Lighthouse scores can vary significantly between runs because they depend on network conditions and server response time at the moment of the scan.
When to use PSI: When you have a specific performance problem and need Google's perspective on what to fix. PSI is the definitive source for Core Web Vitals because it is the closest proxy for what Google actually measures.
GTmetrix: The Performance Deep-Diver
GTmetrix provides performance scoring with detailed waterfall charts that show exactly when each resource loads, how long DNS resolution takes, and where bottlenecks occur. It runs from data centers in multiple geographic locations, which helps diagnose CDN configuration and regional performance issues.
What GTmetrix does well:
- Waterfall diagrams that show the complete loading sequence of every resource on your page
- Geographic testing from multiple locations — useful for diagnosing CDN misconfigurations
- Video playback of your page loading, showing exactly what visitors see at each moment
Where GTmetrix falls short:
- Performance only. Like PSI, it does not check security, SEO, or technology.
- Free tier limitations. Historical tracking, multiple test locations, and API access require a paid plan starting at $15/month.
- Slower scan times (30-60 seconds) because of the video recording and detailed waterfall analysis.
When to use GTmetrix: When you need to diagnose a specific loading bottleneck and the waterfall chart matters. For a deeper look at how PageVital compares to GTmetrix across their full feature sets, see our detailed PageVital vs GTmetrix comparison.
SecurityHeaders.com: The Header Checker
SecurityHeaders.com does exactly one thing: it checks your HTTP response headers and grades them from A+ to F. It tests for Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and Strict-Transport-Security.
What SecurityHeaders.com does well:
- Fast and focused. Results appear in under 5 seconds.
- Clear letter grade that is easy to communicate to stakeholders.
- Links to documentation for each missing header.
Where SecurityHeaders.com falls short:
- Headers only. It does not check SSL certificate validity, HTTPS redirect configuration, or mixed content — all of which are security issues that exist outside of HTTP headers.
- No performance, SEO, or technology analysis.
- No API, no historical tracking, no batch scanning.
When to use SecurityHeaders.com: As a quick spot-check after adding or changing security headers. It is a single-purpose tool that confirms whether headers are present, but it does not give you the full security picture.
PageVital: The Unified Audit
PageVital scans four categories in a single pass — performance, security, SEO, and technology — and produces a composite A-to-F grade. The security audit covers nine checks including SSL validity, HTTPS redirect, and mixed content (not just HTTP headers). The SEO audit checks meta tags, heading structure, canonical URLs, indexability signals, and structured data. The technology detection identifies the CMS, JavaScript frameworks, CDN, analytics tools, and hosting infrastructure behind a site.
What PageVital does well:
- Four-category coverage in one scan. You see performance, security, SEO, and technology results on a single dashboard.
- Composite grading that reflects overall site health, not just one dimension.
- Historical score tracking that shows how each category changes over time.
- REST API and batch scanning included in the free tier.
Where PageVital is more limited:
- Performance diagnostics are less granular than GTmetrix's waterfall charts. PageVital gives you Core Web Vitals scores and key metrics, but does not provide per-resource waterfall timing.
- Field data comes from Core Web Vitals metrics, but does not include the CrUX dataset that Google PSI surfaces.
When to use PageVital: When you need a complete picture of your website's health and want a single score that accounts for performance, security, SEO, and technology together. PageVital is particularly useful for agencies managing multiple client sites, where a unified grade helps prioritize which sites need attention first.
Which Tool Should You Use?
The answer depends on what question you are trying to answer.
"How healthy is my website overall?" → PageVital. It is the only free tool that scores all four dimensions and gives you a composite grade.
"Why is my page slow?" → Start with Google PageSpeed Insights for Core Web Vitals data. If you need deeper waterfall analysis, use GTmetrix.
"Are my security headers configured correctly?" → SecurityHeaders.com for a quick check. PageVital for the full security picture including SSL, HTTPS redirect, and mixed content.
"What do I fix first?" → PageVital, because its composite grading and category breakdown shows you whether your biggest gap is in performance, security, SEO, or technology — rather than assuming performance is the bottleneck.
The Practical Recommendation
For most small businesses, start with a PageVital scan to get the full picture. If PageVital flags performance issues, run a Google PageSpeed Insights test for the authoritative Core Web Vitals data and specific optimization recommendations. If you are debugging a complex loading issue, add a GTmetrix waterfall analysis. Use SecurityHeaders.com as a fast confirmation tool after implementing header changes.
No tool replaces the others entirely. The tools that go deepest in one area (PSI for performance, SecurityHeaders for headers) trade breadth for depth. PageVital trades some depth in performance diagnostics for breadth across all four health categories. The smartest approach is knowing which tool to reach for based on the question you are asking.
Frequently Asked Questions
Are these tools really free?
Yes. All four tools offer genuinely free scans with no credit card required. GTmetrix limits some features (historical tracking, API access, multiple test locations) to paid plans. Google PageSpeed Insights, SecurityHeaders.com, and PageVital provide their core scanning functionality entirely free.
How often should I audit my website?
For most small businesses, a weekly PageVital scan catches configuration drift and new issues before they affect visitors or rankings. Run PageSpeed Insights before and after any significant content or infrastructure change. Check SecurityHeaders.com after any server configuration update.
Do these tools test the same things differently?
Performance is the main overlap area. Google PageSpeed Insights uses Lighthouse scoring. GTmetrix uses its own scoring algorithm informed by Lighthouse data. PageVital scores performance as one of four categories in its composite grade. Because the scoring methodologies differ, the same site can receive different performance scores across tools. This is normal — the underlying metrics (LCP, CLS, INP) are consistent, but the weighting and presentation differ.
Can I automate these scans?
PageVital and Google PageSpeed Insights both offer free API access for automated scanning. GTmetrix API requires a paid plan. SecurityHeaders.com does not offer an API. For continuous monitoring, PageVital's API is the most practical free option because it returns all four category scores in a single API call.
Which tool do SEO professionals use?
Most SEO professionals use multiple tools. Google PageSpeed Insights is standard for Core Web Vitals verification because it reflects Google's own measurements. PageVital is increasingly used for holistic site health audits that include security and technology alongside performance and SEO. GTmetrix remains popular for detailed performance debugging. The trend in the SEO industry is toward comprehensive auditing tools that check security and technical infrastructure alongside traditional SEO signals.