IP-Restricted Links: Share URLs Only With the Right Network

Sometimes a link should only work in one place: inside your office, on your shop's network, or at an event venue. An IP-restricted link does exactly that. It opens normally for visitors on an approved IP address and refuses everyone else.

This guide explains how IP-restricted links work, how to set one up correctly, and where they fit alongside other security measures.

What is an IP address?

Every device that connects to the internet does so through an IP address, which works a bit like a return address on a letter. Most homes and offices share one public IP address for all their devices, assigned by the internet provider.

An IPv4 address looks like four numbers separated by dots, for example 203.0.113.42.

What is an IP-restricted link?

An IP-restricted link is a short link that checks the visitor's public IP address before redirecting. If it matches the address you approved, the visitor goes through to the destination. If it doesn't, they see an error page instead.

On Trimx, you approve one IPv4 address per link.

Practical uses

• Office-only resources. Share a link to an internal dashboard, staff handbook or wiki that should only open from the office network.
• In-store tools. Give shop staff a short link to a stock or ordering form that only works on the store's Wi-Fi.
• Classrooms and labs. Make sure an exam page or lab resource only opens on the school network. See short links for teachers and students.
• Events and venues. Share a link on screen at a venue that only works for people connected to the venue's Wi-Fi.
• Testing. Let your own team preview a page before launch without it working for anyone who stumbles across the link.

How to find the right IP address

This is the step people most often get wrong. You need the public IP address of the network that should have access, not the private address your device shows in its Wi-Fi settings.

• Private addresses often start with 192.168., 10. or 172.16. to 172.31.. These only exist inside your local network and won't work.
• Your public address is what websites see. Search "what is my IP" while connected to the network you want to allow, and use the IPv4 address shown.

If your office has an IT team, ask them for the office's static public IP address.

How to create an IP-restricted link on Trimx

IP-restricted links are available with a free Trimx account.

1. Sign in with email or Google.
2. Paste your long URL on the Trimx homepage.
3. Tick Restrict this link to only work for specific IP addresses.
4. Enter the public IPv4 address, for example 203.0.113.42.
5. Click Shorten.
6. Test the link from the approved network, then from your phone's mobile data. It should only work on the approved network.

Limits you should know about

IP restriction is a useful layer, but it isn't a replacement for passwords or proper sign-in. Keep these limits in mind:

• Home and mobile IP addresses change. Most home broadband and all mobile data connections use dynamic IP addresses that can change at any time. IP restriction works best with a business connection that has a static IP.
• Shared IPs. Everyone on the same network shares the same public IP, so anyone on your office Wi-Fi, including guests, can open the link.
• VPNs change the address. If someone on your approved network turns on a VPN, their traffic appears to come from a different IP and the link won't open for them.
• It's access control, not encryption. It limits who can use the short link, but it doesn't protect the destination page itself. If the content is sensitive, the destination should require sign-in too.

Combining IP restriction with other options

You can pair IP restriction with:

• A custom alias so staff can type the link easily, such as trimx.me/stock.
• A one-time link when a resource should be opened once, and only on-site.
• A QR code printed in a staff-only area. See how to create a QR code for any link.

Frequently asked questions

Can I add more than one IP address to a Trimx link?

Each Trimx link currently supports one IPv4 address. For multiple locations, create a separate short link for each site.

Does IP restriction work with IPv6?

Trimx IP restriction currently uses IPv4 addresses.

Why does my IP-restricted link not work in the office?

Check that you entered the office's public IP address, not a private address like 192.168.x.x. Also check whether the office connection uses a dynamic IP that may have changed, or whether you're connected through a VPN.

Is an IP-restricted link fully secure?

It adds a useful barrier, but it isn't a substitute for sign-in or encryption. Treat it as one layer of protection and keep truly sensitive content behind proper authentication.