Portable Door Alarm

Many door alarms are either a bit too large to stick in a bag and take along or they are wired systems that don't lend themselves to travel anyway. If you're looking for a portable door alarm that allows you to take it along for added security in hotel rooms or to be able to easily install anywhere within your home, there are a few popular options:

1. Door stops.
Door stops are highly portable often weighing only ounces. They require virtually no installation as user merely need to slide them under the door. Most of them offer loud alarms that are very effective in scaring away intruders and alerting you and anyone in the vicinity of an entry attempt. They can also act as a barrier from allowing the door to open although they aren't as secure as some other options.

The only possible drawbacks are that some doors are mounted such that there is little space beneath them making it difficult to get the stop wedged under the door.

2. Door Security Bars
Door security bars which brace a door shut can be very effective at preventing entry. Some of them also have alarms. However, these devices are generally too long in order to pack them in most luggage and, therefore, they aren't considered portable in that sense. However, if you're interested in a these you can find these door security devices here.

3. In-Door Alarms
Some door alarms have a main unit that attaches to the door, usually hung over the door handle with prongs that are inserted into the opening between the door and door jam. These devices are also highly portable and easy to install for temporary use. They also provide alarms loud enough to scare off intruders but won't act to prevent entry beyond that.

The potential drawback with these types of portable door alarms are in situations where the space between the door and the jamb is a bit too wide. In these instances, the prongs can dislodge automatically rendering the alarm useless or resulting in false alarms. A small shim can help to remedy this issue. Some of these alarms are more versatile however and can also be used as a personal alarm or attached to other items to protect them from theft.

4. Door Alarms Which Mount with Adhesive
These portable door alarms are also small and light weight and require just seconds to install. However, because of the adhesive they are intended to stay where they are mounted. To use them for travel, strong two way tape would need to be used for re-mounting. Again, these alarms can provide a deterrent as they scare off intruders and alert users but perform no means of preventing entry beyond this.