Web Filter Lookup: Domain Category Check for Any Website
Enter a domain to see the web filtering categories it carries: the labels a firewall, DNS filter or secure web gateway uses to allow, block or log it. Results come from our database of 120 million domains in 58 categories.
Look Up a Domain
This domain is one of the 120 million in our database. Vendors license the full file for their filters: see the web filtering database.
Free lookups use a demo slice of the database. Licensed customers get the full data.
What a web filter lookup tells you
A web filter lookup answers one question: which content categories a filter sees for this domain. Filters rarely judge sites one by one; they apply a policy to categories, so the category decides whether a site is allowed, blocked or logged.
Short answer
Type a domain and the lookup returns the categories stored for it, out of our 58 web filtering categories. If one of those categories is blocked in a policy, a filter using this data would block or flag the site for the users under that policy.
Which categories
Every label the domain carries in our data, such as Streaming Media or Online Banking. Busy sites that do several things carry several labels.
Why a site is blocked
When a site is blocked on a network, its category is usually the reason. Compare the labels with the categories your policy blocks.
What a rule would do
Admins check a few important sites before switching a category on, for example Gaming for one group, so the rule does not catch tools people need.
Where it belongs
When known, the country attributed to the domain appears too. It helps with regional rules and with spotting look-alike sites.
Four names for the same check
People search for this check under different names. They want the same thing, with small differences in what they expect back.
| What people search | What they usually want to know | What this page returns |
|---|---|---|
| Web filter lookup | Why a filter allows or blocks a site, or how it will treat a site | The categories a filter acts on for that domain |
| Domain category check | The category of a domain before writing or changing a rule | Every category stored for the domain, plus its country when known |
| Website category lookup | What kind of site something is, in plain terms | Labels from one consistent set of 58 categories |
| URL category lookup | The category behind a link that includes a path | The category of the domain; the path is ignored because categories describe the whole site |
Checking many sites at once? The bulk categorization tool takes up to 10 domains at a time, and the URL checker takes full links and flags phishing and malware.
Sample Lookup Results
See the kind of detailed categorization data returned for each domain in our database.
Domain Coverage by Category
Explore the distribution of 103.7 million domains across Web Filtering and IAB content categories. These charts show the global scale of our classification coverage.
What each lookup result means
A web filter lookup returns a short answer, but each part tells you something. Here is how to read it.
Domain
The hostname we matched, with any leading www removed. Paths and query strings are ignored, because categories apply to the whole site.
Category tags
One or more of our 58 web filtering categories. The first tag is the primary category; later tags describe smaller parts of the site.
Country
The country attributed to the domain, shown only when one is known. Useful for regional policy and for spotting look-alike sites registered far from the real brand.
Not found
The free tool searches a demo slice of the database. A missing result here does not mean the domain is uncategorized in the full 120 million domain set.
Subdomains: the lookup uses the hostname you enter, minus any leading www. If a subdomain such as a shop or blog section has no entry of its own, try the main domain as well. New sites: a domain registered in the last few days is categorized from the content it shows at launch, then checked again after a week and after a month.
The 58 web filtering categories explained
Every result uses the same 58 categories. Tiles marked with a shield are the ones most policies block by default; the full definitions live on our web filtering categories page.
Shield tiles: commonly blocked categories. Your organisation's policy decides what is actually blocked.
How to read multiple categories
Many websites do more than one thing, so a domain can carry several categories, ranked by how much of the site each one describes.
Most filters base their main decision on this one. A news site with a sports section is primarily News/Media.
Worth a warning or report even when you allow the site. A game portal with betting features may show Gambling here.
Helpful for context and fine-grained policy, such as a forum inside a software vendor's site.
Rule of thumb: block when a blocked category is primary; warn or log when it appears lower. Strict environments such as schools may block on any position.
Reading real results: six worked examples
These rows are real entries from the database, with the primary category first. The right-hand column shows how a typical office policy might read each result.
| Domain | Categories, primary first | How a policy might read it |
|---|---|---|
| linkedin.com | Social NetworkingJob Search/CareersBusiness | A Social Networking block stops it. If recruiters and sales need it, allow it for their group rather than lifting the social block for everyone. |
| youtube.com | Streaming MediaSocial Networking | Either a streaming block or a social block can catch it. Check both switches before you decide how to treat it. |
| twitch.tv | Streaming MediaGaming | If your filter acts on every listed category, a Gaming block stops it even where streaming is allowed. |
| reddit.com | Social NetworkingForums / Message BoardsCommunity Sites | Three labels for one community platform. Blocking forums alone is enough to stop it in filters that act on all labels. |
| paypal.com | Financial ServicesOnline Banking | Rarely blocked, but useful in rules about traffic inspection. Many teams leave banking and payment sites out of SSL inspection. |
| nytimes.com | News/MediaPolitical | Political appears as a second label. Worth knowing if you log political content, but no reason to block a news site. |
Find out whether your filter acts on the first category only or on every category it receives. That one setting explains most surprises when a site is blocked or allowed.
Three questions to ask of every result
Is a blocked category anywhere in the list?
Read past the first label. A site can be blocked through its second or third category, depending on how your filter is set up.
Does the primary label match what users do there?
The first category describes most of the site. If staff use only one small part, a targeted exception may serve better than a policy change.
Would one rule catch other sites you need?
Before blocking a category to stop one site, look up a few important sites in the same category. Category rules are broad by design.
How results map to firewall categories
Firewalls, DNS filters and secure web gateways each use their own category names. A lookup here shows our category; your product may label the same site differently.
| Our category | Names you often see in filter products | What to check |
|---|---|---|
| Malware / Phishing / Suspicious | Malicious sites, phishing, security risk, newly observed | Some products split these into several separate categories |
| VPN / Proxy / Anonymizers | Proxy avoidance, anonymizers, filter bypass | Whether VPN services and web proxies are separate |
| AI / LLM Tools | Generative AI, AI applications, artificial intelligence | Newer products have this; older ones fold it into technology |
| Adult | Pornography, adult content, sexually explicit | How nudity in art or education is handled |
| Streaming Media | Streaming video, media streaming, internet radio | Whether music and video streaming are separated |
What to do if you disagree with a category
Sites change, and some sit on the line between two categories. Before acting, check the site yourself.
Visit the site safely
Open it on a managed device or isolated browser, not on a machine holding sensitive data.
Look beyond the homepage
Check menus, linked sections and what most pages are about. The category describes the whole site.
Check all the tags
The category you expected may be there as primary or secondary. Read the full list before deciding it is wrong.
Consider recent changes
A domain may have changed owner, moved to new content or become parked since it was last refreshed.
Use a local override
Every serious filter lets admins allow or block a single site. That is the fastest fix for your own network.
Running a filter built by a vendor? Raise the site with that vendor, since they control how categories are applied in their product.
When a site is miscategorized for your policy
Most complaints are not about a wrong label but about a label that clashes with one policy. Either way, the fix sits in your own filter: an allow list or a deny list, applied to the smallest group that solves the problem.
A site people need is blocked
Add the domain to the allow list for the group that needs it, not for the whole organisation. Record who asked and why.
An unwanted site gets through
Add it to the deny list straight away. Then look up similar sites to see whether a category rule would cover the whole group.
Only one section causes trouble
If your filter inspects full URLs, as most secure web gateways can, use a path rule. A DNS filter only sees the domain, so it can only allow or block the whole site.
The category is right but too broad
Keep the category rule and add named exceptions. Or split users into groups with different category policies, which is easier to explain later.
Allow list, deny list or category rule?
| Tool in your filter | Use it when | Watch out for |
|---|---|---|
| Allow list | A specific site must work for a specific group, whatever its category | Allowing a shared host or delivery domain can open far more than one site |
| Deny list | A specific site must never load, whatever its category | Lists go stale, and new domains of the same kind are not covered |
| Category rule | A whole type of site should be treated the same way | Sites carry several categories, so one rule can catch more than you expect |
| Time-limited exception | Someone needs access for a project, an audit or an investigation | Exceptions without an end date tend to stay for years |
Common mistakes with overrides
- Allowing a parent domain to fix one subdomain, which opens every other subdomain as well.
- Forgetting the extra domains a site loads from, so the page opens but video, images or sign-in fail.
- Adding exceptions without a note, so a year later nobody knows why a rule exists or whether it is still needed.
- Expecting a public lookup to change a filter. A lookup only reports categories; the admin of your filter decides what it allows.
Nothing on this page changes what any filter does. For your own network, the allow and deny lists in your filter are the right tool, and our guide to custom policy management covers how to keep them tidy.
Bulk lookups for teams
One domain at a time is fine for a quick check. Teams auditing logs, onboarding a customer or testing a policy need whole lists.
Audit a log export
Categorize thousands of domains from a firewall or DNS log to see what your users actually visit.
Test a policy
Run your critical sites and a set of known risky domains through the same categories before switching policy on.
Automate it
Licences include a lookup API, and the full database runs inside your own systems as CSV, Parquet or JSON.
Start with our bulk categorization tool, or read about bulk domain lookup workflows and the domain categorization API.
Web filter lookups for vendors, at scale
A filter product makes a category decision for every request its users send, so vendors do not use a web page. They load the category file into their own systems and use the lookup API that comes with a licence for single checks.
| This lookup page | Lookup API (with a licence) | Database file (licensed) | |
|---|---|---|---|
| Made for | Admins checking one site | Products that need an answer for one domain on demand | Filters, gateways and DNS resolvers that decide in line |
| Coverage | A sample of about 4 million popular domains | The domains in your licence | Up to 120 million domains, by tier |
| Where it runs | In your browser, on this site | Called from your own code | Inside your own systems, air-gapped if needed |
| Freshness | Follows the sample | Same data as the file | Daily delta files for new domains, monthly refresh for the rest |
| Formats | On-screen result | JSON | CSV, Parquet or JSON, with exports such as DNS RPZ, hosts files, EDL and PAC files |
| Use in a product | Not allowed | Allowed under the licence | Internal, OEM or group-wide licence |
How vendors put lookups into a product
- Pick the coverage. The 20 million most visited domains cover almost all traffic; the full 120 million adds the long tail, where many new and short-lived sites sit.
- Map the categories once. Match our 58 categories to the list your product shows customers, in a mapping table you own and can change.
- Load the file locally. Put the data into your own lookup store, so every decision is answered inside your network with no outside call.
- Apply the daily deltas. New domains arrive every day and are checked again after a week and after a month, as many sites add content after launch.
- Use the API for the edges. Support teams and back-office tools can call the lookup API for spot checks and single domains.
- Give customers overrides. Every network has local exceptions, so expose allow and deny lists next to the category switches.
Read more about the web filtering database download, OEM licensing for products, the block list formats we export and real-time URL classification.
Web filter lookup FAQ
Why did my domain return no category?
The free lookup searches a demo slice of the database, around 4% of the 120 million domains. A missing result usually means the domain is outside that slice, not that it is uncategorized.
Can I look up a full URL with a path?
Yes, but categories are assigned per domain. The path is ignored and the result describes the whole site.
Why does my firewall show a different category?
Each filter product uses its own category list and its own data, so names and results can differ. Compare what each category covers, not only its name.
How often are categories updated?
About 300,000 newly registered domains are categorized every day and checked again after a week and a month. All other domains are refreshed monthly.
Will you change a category if I ask?
We review feedback, but we do not promise changes or timelines. For your own network, a local override in your filter is the quickest route.
Can I use these results in my product?
Not from the free tool. Vendors license the database for internal use or OEM embedding; resale or publication of the raw data is not allowed.
What is a web filter lookup?
A check that shows which content categories a web filter would see for a domain. Filters allow or block categories, so the result explains how a site is treated under a given policy.
Is a domain category check the same as a URL category lookup?
Almost: categories here describe the whole domain, so a URL with a path returns the category of its domain. Filters that inspect full URLs can add their own path rules on top.
Why does one website show several categories?
Many sites do more than one thing. The database stores several categories per domain, ranked by how much of the site each one describes, so a rule can catch a site through its second or third label.
A site is blocked on my network. Can this lookup unblock it?
No: the lookup only shows categories and does not change any filter. Ask the admin of your network's filter, who can add the site to an allow list.
What should I do if a site is miscategorized for my policy?
Use the allow and deny lists in your own filter, scoped to the users who need the change. That fixes the problem on your network straight away, whatever the category says.
Can vendors run web filter lookups in bulk?
Yes, under a licence. Vendors load the database file into their own systems and use the lookup API that comes with the licence for single checks.
Need every domain, not a demo slice?
License the full database: 120 million domains, 58 categories and the IAB Content Taxonomy in one file, with daily deltas and a lookup API. Starter database tiers from $999; enterprise and OEM licences are quoted per deployment.
Why Use Our Domain Lookup Tool?
A quick way to see how a site is categorized before you change a policy or answer a ticket.
120 Million Domains
Our database covers the vast majority of active domains on the internet, with regular re-classification to keep data fresh. Schools use this lookup to verify educational resources before approving them through our web filtering solution for schools and educational institutions.
One Consistent Taxonomy
The same 58 categories are used in this lookup, in the API and in the licensed database files, so a result here matches what your filter will see.
Multi-Category Support
Domains can belong to multiple categories simultaneously. A news site covering technology will show both News and Technology tags.
Regular Refreshes
Categories follow websites as they change. New domains are checked again after a week and after a month, and all other domains are refreshed monthly.
API Access Available
Integrate domain lookup directly into your applications with our REST API. Process up to 1,000 lookups per second with sub-50ms response times, or run bulk domain lookups for entire lists in a single request.
Security Categories Too
The same lookup shows whether a domain sits in a security category such as Malware / Phishing / Suspicious, so one check covers both content and risk.
How Domain Lookup Works
Three simple steps to categorize any domain on the internet.
Enter a Domain
Type or paste any domain name into the search field. No need to include http:// or www. Just the domain is enough.
Instant Classification
Our system queries the database of 120 million pre-classified domains and returns matching categories in under 50 milliseconds.
Review Results
View detailed category assignments, country of origin, and metadata. Export or integrate results via API.
Who Uses Domain Lookup?
Organizations across every industry rely on domain categorization data for security, compliance, and content filtering.
Enterprise IT Teams
Quickly verify domain categories when configuring web filters, troubleshooting access issues, or auditing employee browsing policies.
Schools & Libraries
Educators use domain lookup to check if a site is categorized correctly before requesting whitelist or blacklist changes for student networks.
Security Analysts
SOC teams check the category of a suspicious domain from an alert or log line before deciding how to respond.
Need More Than Manual Lookups?
Integrate our domain categorization API into your products and workflows. Process thousands of domains per second with enterprise-grade reliability.