&nbsp;Yes the alarm will trigger with the siren without Wi-Fi Connection! You do not need Wi-Fi for the alarm to trigger the siren as the system display connects to the sensors using radio frequency NOT Wi-Fi.&nbsp;
However, without Wi-Fi you will not get any notifications. You need Wi-FI connection to remotly arm, disarm, get notifications and change settings. So without Wi-Fi you will not get notifications.
If you do not have Wi-Fi in your area or want to be able to use the Call Feature, a feature that will call up to 5 pre programmed phone numbers when the Alarm has been triggered, you can purchase a 4G Network Supported SIM card which costs approximately $15 per month. <a href="https://osigodirect.kb.help/do-you-need-a-sim-card-to-receive-text-alertsnotifications-from-the-osi-alarm-system/">Learn More about this feature here</a>&nbsp;
*Note: Due to 3G Networks being phased out internationally including Cananda and USA, we recommend purchasing the 4G Model if you are wanting to use a SIM Card. Currenty only our <a href="https://www.osigodirect.com/osi-wi-fi-alarm-system-14-no-monthly-fees/">14 Piece Alarm Kits</a> sold now supports 4G Network SIM Cards. The 4G 8 Piece Alarm kits will be sold early this summer.

 Yes the alarm will trigger with the siren without Wi-Fi Connection! You do not need Wi-Fi for the alarm to trigger the siren as the system display connects to the sensors using radio frequency NOT Wi-Fi. 
However, without Wi-Fi you will not get any notifications. You need Wi-FI connection to remotly arm, disarm, get notifications and change settings. So without Wi-Fi you will not get notifications.
If you do not have Wi-Fi in your area or want to be able to use the Call Feature, a feature that will call up to 5 pre programmed phone numbers when the Alarm has been triggered, you can purchase a 4G Network Supported SIM card which costs approximately $15 per month. Learn More about this feature here 
*Note: Due to 3G Networks being phased out internationally including Cananda and USA, we recommend purchasing the 4G Model if you are wanting to use a SIM Card. Currenty only our 14 Piece Alarm Kits sold now supports 4G Network SIM Cards. The 4G 8 Piece Alarm kits will be sold early this summer.

Will the Alarm still trigger with Siren without Wi-Fi Connection?

Does the OSI Alarm System communicate with a central station?

Does the OSI Alarm System  uses 2.4 GHz or 5.0 GHz?

2G Network service is now obsolete for the current OSI Alarm System. Will a 4G Model be available soon?

How do you turn off the Arm and Disarm Notifications? 

How to change OSI Alarm Language on the Display

Black Screen Issue

How to set the Motion Sensor so it is NOT Active when I Arm the Alarm System in as "STAY" (such as before going to bed)

How to turn on Alarm Notifications for your OSI Alarm System - Android Phones

When i program the alarm with Stay Arm Active (without delay) It has no delay when entering but still has a delay when exiting

What is included in the OSI Smart Alarm System?

Does the OSI Alarm System let you know when a door or window is open?

Can I change Siren Duration for OSI Alarm?

The Smart Life app is not working properly and is giving false triggers.

How to connect Google to the OSI Wireless Alarm System OSI-ALM-KIT-W

Does the OSI Wireless Alarm System connect to 2.4G or 5G Wi-Fi?

Alarm Display is Frozen! What do i do? (how to reset alarm display)

Does the OSI Smart Wifi Alarm System work with apple?

Do you sell smoke and moisture sensors that connect to the OSI Alarm System? 

Can you use 433mhz wireless sensors with the OSI Smart Alarm System?

How do you add more than one user password on the OSI Alarm System?

How loud (dB) is the stock siren that comes with the OSI Smart Alarm Kit?

Do you need a sim card to receive text alerts/notifications from the OSI Alarm System?

The OSI Alarm Display is too bright! Can i Dim it or turn it off?

Does the OSI Alarm System work outside the USA? 

Is the OSI Wireless Strobe Siren accessible via API

Is the OSI Alarm System capable of partitions? 

Open Door alarm alerts for on display stay red after i delete logs. How do i fix this?

How to you replace the OSI Smart Wi-Fi Alarm System Back-up Battery?

How to share your OSI Wi-fi Alarm Account with Smart Life App

Does the OSI Alarm System need Wi-Fi connection to work?

Is the OSI Alarm System a standalone alarm system?

Does the OSI Alarm System support 3rd party alarm monitoring services? Also what is the GSM for?

Can i use an external tuya smart switch with the osi security system to trigger an alarm horn? if so, what would the communication be between the systems?

How can i get more rfid tags programmed?

I forgot my password for the OSI Alarm System and i am locked out!

Can you turn off the motion detector and still arm the rest if the system if someone is home and in the house?

How to set up the OSI Wireless Alarm System (quick-start guide)

Can a second OSI Smart Alarm display be linked together?

Can't connect to Google Fiber!

Where can i download the Quick Guide for the OSI Wi-Fi Alarm System Kit (model OSI-ALM-KIT-W)?

How many audible devices will the OSI Alarm System accept?

OSI Wireless Strobe Alarm Siren Unboxing Setup and install

What does the OSI Smart Alarm System kits include?

Does the OSI Smart Alarm display a camera or just shows alarm functions?

How can I monitor for open zones before arming the OSI Smart Alarm System? 

Can you adjust the entry delay timer on this alarm system?

I am locked out! How do i get into the OSI Alarm Display? Is there a default passcode?

Alarm display indicates the sensors have Low Battery on my new system.

Can you buy extra sensors and sirens for the OSI Smart Alarm System?

Can you add smoke detector or water sensors to the OSI Wifi Alarm System?

Will the OSI Alarm System still work on Back-up battery during the power failure?

How do you create a code for the OSI Alarm System

How to Program RFID Tags (and how do they work?)

What is the difference between EZ Mode and AP Mode in Smart Life? is AP Mode more beneficial?

Connecting OSI Smart Alarm Wi-Fi (GSM) to Smart Life app with Android using AP Mode (recommended)

Wi-Fi Connection Issues? Use SoftAP Configure! 

Does the OSI Alarm System audibly announce which door is open? 

How to Arm & Disarm OSI Smart Alarm System with Google?

How can I monitor for open zones when the system is not ARMED?

Can the OSI Alarm System display which door is open?

Is there a limit on the number of phones I can use the phone app with to control the alarm system?

Can i add door locks to the OSI Alarm System via zigbee or zwave

Can the OSI Alarm System be programmed to automatically arm and disarm every day/night?

Does the OSI Alarm System connect to central stations?

What is the power requirement for the OSI Alarm System control panel? Power Adapter Specs

What is the OSI Alarm RFID Tag Frequency?

What is "Doorbell" Mode on the OSI Alarm System?

Do you have "Glass Break Sensors" available for the OSI Smart Alarm System?

Door sensor is not working even after putting in new battery, but when I press the button on the back it works. 

How can i tell when the battery is low on any of the Alarm Sensors?

OSI MINI ALARM: What do the different "Zone Attributes" mean?  (also called "Mode" on Alarm Display)

Connecting OSI Smart Alarm Wi-Fi (GSM) to Smart Life app with Apple IOS using AP Mode (recommended)

SENSOR - How to Install: Placement Tips & Installation 

How to use a SIM Card with the OSI Wi-Fi Alarm System

Troubleshooting - 4G OSI WiFI Alarm System:  Alarm Display has No Power

OSI Wi-Fi Alarm System (no siren or doorbell sound coming from panel or horn)

How to change the Exit & Entry Delay time on the Smart Life app

SENSOR - Information: Max Distance, type of Batteries & Battery Installation

How to change the Exit & Entry Delay time on the OSI Alarm Display

Can I use the alarm sensors in my detached garage or shed?

What batteries are included with the OSI Smart Wi-Fi Alarm System

How to fix Unresponsive Touch Screen Display

SENSOR - How to Connect to OSI Alarm System: How to add (or re-add) sensors with Smart Life App

Why does the OSI wireless strobe siren flash every 10 seconds?

What is the Difference between System Password & User Password

SENSOR - All Q & A HELP

How long should the Back up battery supply power to my OSI Wi-Fi Alarm System during a power failure

How to add Sensors from Touch Screen Alarm Display

OSI ALARM (with Display): What do the different "Zone Attributes" mean?  (also called "Mode" on Alarm Display)

How to turn off alarm panel keypad tones

OSI Mini-Alarm: Recommended settings to use for contact sensors used on windows

OSI Wi-Fi Alarm: Recommended settings to use for contact sensors used on window

OSI Mini-Alarm: Recommended settings to use for PIR Motion Sensors

OSI ALARM (with Display): Recommended setting to use for PIR Motion Sensors

OSI Mini-Alarm: Recommended settings to use for contact sensors used on doors

OSI Wi-Fi Alarm: Recommended settings to use for contact sensors used on doors

Connecting OSI Smart Alarm Wi-Fi (4G) to Smart Life app with an Android or Apple IOS (recommended)

How to set local weather on display (for 4G System only)?

How to Replace the Motion Sensor Batteries

OSI Wifi Alarm System

Hi, how can we help?