Speed
Server response time, load time, compression, HTTP/2 and the number of scripts and stylesheets.
Free tools
How fast and secure is your website?
Enter your address. Within a minute you see a percentage for each area: speed, structure, visibility in Google, security, email and how up to date your site is. Plus the most important improvement.
Speed, structure, visibility in Google, security, email and whether your site is up to date. Free, done in under a minute.
- Connecting
- Checking SSL and https
- Measuring speed
- Security headers
- SPF and DMARC
- Reading robots.txt and sitemap
- Opening pages like Google
- Structure and schema
- Is the site up to date?
What we check
The same points we review for new customers, including web shops with millions in revenue.
Security
HTTPS, redirects, SSL certificate, security headers and whether your server reveals its software version.
SPF and DMARC: can someone else send email on behalf of your domain?
SEO & mobile
Page title, meta description, headings, mobile friendliness and accessibility.
Structure
How your page is built, as GTmetrix measures it: blocking scripts, browser cache, images, schema, headings and Open Graph. Tailored to your system.
Visibility
Can Google crawl everything? We read your robots.txt and sitemap, open pages like Googlebot and look for noindex, broken links, duplicate versions and soft 404s.
Up to date
Are your WordPress, jQuery or PHP up to date, when did something last change, is your blog still active and is the year in your footer correct?
Has your password ever been leaked?
Check whether a password appears in known data breaches. Your password never leaves your browser. We only send the first five characters of an encrypted version (SHA-1) to the Have I Been Pwned database and compare the rest on your own device.
Do you use the same password in several places? Then one leak is enough to get in everywhere. A password manager and two-step verification solve that.
How many sites link to you?
Backlinks are still one of the strongest signals for Google. See how many domains link to a site, how strong they are, and the top ten. Also works for your competitor.
Data from one of the largest backlink databases in the world, a few days old. Without an account 2 checks per day, with a free account 10. The full list with filters and export is in Edge › Competitors.
Mini SEO check
Have your homepage checked for title, description, headings, schema and 404 handling.
Go to the SEO check →Domain name search
Check right away if your name is still available, in more than ten extensions at once.
Search for a domain →How DDoS protection works
See in an animation how attack traffic is stopped before it reaches your site.
View the animation →Our customers
Companies with millions in revenue trust us with their tech.
For web shops and platforms with millions in annual revenue, we are the technical lead and we handle the SEO. We build and manage the servers, monitor speed and security, and make sure they get found. You can use the same knowledge and the same servers at Netslim for your own site, whether it starts small or is already large.
Website of the Year 2026 · certified
Approved by the expert panel.
The independent expert panel of Website van het Jaar has reviewed and approved netslim.nl: on ease of use, speed, reliability and design. That gives us a chance at a nomination. What we build for ourselves, we build just the same for you.
About Website of the Year- SEOAudits, technology, content and reporting
- Technical leadArchitecture, performance and releases
- SecurityHardening, monitoring and DDoS protection
- HostingShops with hundreds of thousands of products
Goes well with this
Often chosen together
Netslim Speed
Page cache, WebP and smaller videos. Your site faster in an afternoon.
per site per year→Netslim SEOSEO plugin for WordPress: check, AI meta and sitemaps for up to millions of products.
per site per year→Edge SEORank higher in Google without rebuilding your site: fixes go live via the edge.
per site per month→