What is a WiFi Captive Portal?

Think of a captive portal as a checkpoint. You connect to WiFi, the network gives you a basic connection, then holds you at a simple web page until you do what the venue needs, accept terms, confirm an email, enter a voucher, or log in. Once you pass that step, the network opens the gates and your device gets normal access.

The splash page is the screen you see. The captive portal is the system behind it that decides who gets through, for how long, and with what limits. It controls login options, email or social or vouchers, sets bandwidth and time limits, and records consent so the business can meet policy and privacy requirements. Same idea works on wired guest networks too, not just WiFi.

At a high level the flow is simple. Join the network, get an IP, the network restricts what you can reach, and redirects you to the portal. Complete the step, the controller updates your access, and your apps work as expected. If the login page does not appear right away, that is usually the browser or device being careful with security, which I cover in the next section with quick fixes and testing tips.

So, in a nutshell:

• A captive portal is the mechanism that runs the guest WiFi login process. Your customers do not see it when accessing the guest WiFi. But it is the captive portal that makes the process possible. 
• A splash page is the actual page that customers see when accessing the network. This is what they experience as the physical manifestation of the process. However, the process itself is run by the captive portal. 

Why use a captive portal?

First and foremost, a captive portal is a system that allows you to provide free internet access to customers.

But captive portals offer other benefits, too.

Provide seamless WiFi experience to customers.

Thanks to a captive portal, you can provide a simple way for customers to access the internet at your hotel, restaurant, or bar.

What I mean by that is that the captive portal will make it easy for customers to log into your guest WiFi. They won’t have to do anything to set up the connection; just log in and they’re in.

Similarly, the captive portal will recognize if someone is a returning visitor and will display log in screen for them, allowing them to access the network fast.

Help you capture leads and build your marketing list.

Customers will have to log in to the captive portal to access the network. This means that the portal can help you generate new leads, collect their contact details, and forward that data to your other marketing tools (e.g., email marketing software, etc.)

What’s more, captive portals like MyPlace offer advanced user analytics, so that you can combine customers’ details with behavioral data to create even more focused marketing campaigns.

Control the bandwidth and limit guest WiFi usage if needed.

In theory, you’d want every customer to be able to connect to your network. However, in practice, there might be situations where you might need to limit guest WiFi usage.

For example, you might be close to reaching your bandwidth quota. Or you might be experiencing low bandwidth and want to limit the number of devices accessing the network.

A captive portal gives you complete control over how many devices can use the network at a time, helping you to control the bandwidth and usage.

Collect customer feedback with various surveys, like NPS.

FACT: Collecting customer feedback is one of the most beneficial strategies for any business. It’s how you can identify what’s working and which areas of the business would do with some improvement.

But the challenge is that it’s hard to simply ask customers for feedback when you’re going through the bustle of a normal day.

Luckily, that’s where a captive portal could help, too. With a captive portal, you can display surveys, like NPS or CSAT, directly on the splash page, asking customers to provide their feedback.

Show notifications and promotions.

You can display notifications and promotions on the splash page through the captive portal.

For example, you can include information about today’s specials at the hotel’s restaurant on the splash page to entice more people to dine there. You can also notify patrons about special offers to generate more repeat business. You can promote upcoming events or simply include an important announcement.

In other words, with a captive portal, you can connect with and promote your business to every customer accessing your guest WiFi.

Ask for reviews and star ratings.

Finally, you can also use a captive portal to entice customers to leave review of your business on Google, Yelp or other platforms. Like with the other benefits, this also happens on a splash page.

What businesses need a captive portal for their WiFi?

By its nature, a captive portal is required in any instance where a business wants to provide customers with access to the internet from its premises.

Most commonly, captive portals are used by businesses such as:

• Hotels
• Restaurants
• Coffee shops
• Bars
• Venues and conference spaces
• Airports
• Shopping centres
• Bars
• Pubs
• Public spaces like museums
• Cinemas
• Gyms
• Hospitals
• and more.

How does a WiFi captive portal work?

I called the captive portal a mechanism, and I think it makes sense to see how the system works.

A quick note, the process is technical, but I’ll keep it simple and explain any jargon as we go.

The simple flow

1. A person connects to your guest network.
2. DHCP gives their device an IP address so it can talk on the network.
3. Until the person signs in or accepts terms, the firewall or gateway limits access.
4. The network redirects the person to a web page in the browser, the splash page.
5. The person completes the step you require, accept terms, enter a code, or sign in.
6. The controller lifts the restriction and the device gets normal internet access.

That’s the basic loop most venues run.

What your device actually does behind the scenes

Modern devices try to detect captive portals automatically. On Apple devices, a built-in helper called Captive Network Assistant probes a test URL and, if it sees a portal, opens a lightweight login window so people do not have to hunt for a browser tab. Windows does a similar connectivity check and can open the page right away when it detects a portal.

If you like specifics, platforms use known test URLs for this. When the response is not what they expect, they assume a portal is in the way and trigger the login. That is how your guests get the little popup window on phones and laptops. Ref: Wikipedia

Why the login page sometimes does not appear

Two common reasons.

1) HTTPS and HSTS. If the first site a person tries to open is HTTPS, the browser will not follow a redirect to your portal. With HSTS, some sites refuse all workarounds. The right fix is to rely on the system popup or start with a non-HTTPS page for testing. A simple tip that works almost everywhere is to visit http://neverssl.com which is designed to let the portal catch the request.

2) VPN or secure agents on the device. Security clients like Cloudflare WARP can hold all traffic in a tunnel before login. That blocks the portal until the user authenticates or pauses the client. If your venue uses a client like that, add a note on the splash page and give people a clear retry path.

Standards note, for completeness

Some networks advertise the portal URL straight to devices during connection. They do this using DHCP or Router Advertisements defined in RFC 8910. You do not need to implement or mention the RFC to guests, but it helps you understand why some devices feel faster at showing the login.

Quick checks when something feels stuck

• Forget and rejoin the network, then wait for the system popup.
• If no popup shows, open a browser and try http://neverssl.com.
• If a VPN or WARP-style client is active, pause it, log in, then resume.
• If you still see warnings on an HTTPS site, go back to the popup window or a plain HTTP page and complete the login there.

Common captive portal issues and quick fixes

• The login page doesn’t appear. Try opening a non-HTTPS page or disable VPN/WARP temporarily. Then retry.
• Why do I get certificate warnings? HTTPS + HSTS prevents interception. Use the system’s CNA window or navigate to a non-HTTPS test page.
• Apple devices don’t show the popup. Confirm CNA isn’t bypassed and the detection URL is reachable.

How to Set Up a Captive Portal for WiFi

We’ve covered quite a lot of information about what a captive portal is, how it works, and what are it’s elements, including the splash page. 

So, as the last part of this guide, let’s review what sort of hardware and software do you need to create a captive portal for your location. 

And as a matter of fact, you only need three elements to do so:

#1. Router/Access Point

A router or access point in a captive portal is a device that connects the customer’s device – phone, laptop, etc. to the internet. 

When they try to connect to a network, the router/access point directs the device to the splash page, where they log in, accept terms, or enter a code. 

The router/access point manages this connection and ensures only authorized users can use the network, enhancing security and controlling access.

#2. Captive Portal Software

As I’m sure its name suggests, this software manages the captive portal for you.  

When your customers join a network, the captive portal software ensures only authorized users access the internet, tracks user activity for security, and can display custom messages or ads. 

It runs on the network’s server or router, handling user authentication and providing a secure, controlled way to grant internet access.

Example of a captive portal software

MyPlace (disclaimer – this is my tool) is a dedicated captive portal software that helps brick-and-mortar businesses – restaurants, hotels, coffee shops, bars, and many others – manage guest access to their WiFi networks. 

Access is managed by a captive portal, where WiFi users are required to enter registration information to gain access.

Thanks to MyPlace, venues can capture valuable email and marketing data on their customer, giving them an incredible opportunity to remarket and/or upsell to the customer after they have left the physical location.

In addition to primary email data, MyPlace incorporates behavioral and geo data to provide additional context.

Finally, MyPlace integrates directly with many email marketing platforms, such as Mailchimp or Klaviyo, allowing venues to add collected emails to their mailing lists. 

#3. Splash page customization tool

The final element is software that allows you to create and customize splash pages. 

And in short, splash page software creates and manages the first webpage your customers see when connecting to a public Wi-Fi network. 

This page can show login options, advertisements, terms of service, or other information and helps businesses communicate with users, collect data, and ensure users agree to specific terms before accessing the Internet. 

The software runs on the network’s server or router, making it easy to customize and control the user experience on public networks.

NOTE: MyPlace also creates splash pages for you, so you don’t need a separate tool for that. 

And that’s it…

That’s all there is to know about WiFi captive portals. All that’s left for you is to start setting up your captive portal and a splash page and launch your WiFi marketing campaign. 

Good luck!

Captive Portal – FAQ

References

• Microsoft Learn on captive portals and user experience.
• Apple Support on using captive networks.
• Cloudflare Docs explaining captive-portal behavior with secure clients.
• RFC 8910 summary page.
• Wikipedia and TechTarget defining captive portal.

Ready to compare captive portal tools? See our best captive portal software roundup.