Surv · Guides
Offline emergency preparedness apps, compared
Alert apps, offline reference guides, checklist tools and paper: which ones still work when the network does not, and what to check before you need them.
In this guide5
The only question that matters on the day
Preparedness apps divide cleanly on one criterion: what happens when there is no signal. Everything else is secondary, because the situations these apps are for are the situations that take the network away.
Alert apps need a connection by definition — they exist to receive warnings. Offline reference guides store their content on the device. Checklist tools may do either. Paper, which belongs in this comparison, needs nothing at all.
Where each family stops working
An alert app with no signal shows its last known state, which can be worse than showing nothing. An offline guide with no signal shows everything it shipped with, and nothing newer. A cloud checklist with no signal may show an empty list.
The honest conclusion is that these are complements, not rivals. Official alerts come from your national system; reference material is what you keep locally. Ready.gov recommends keeping information that does not depend on power or connectivity.
Criteria to check before you need them
Test the app in airplane mode on the day you install it, not on the day you need it. That single test answers more than any feature list.
The remaining criteria are about trust and weight: where the content came from, whether it names its sources, whether it asks for an account, and how much room it takes on the device.
| Criterion | Alert app | Offline guide | Cloud checklist | Paper |
|---|---|---|---|---|
| Works with no signal | No | Yes | Often not | Yes |
| Works with no battery | No | No | No | Yes |
| Content can be updated | Continuously | When online | When online | Never |
| Tells you what is happening now | Yes | No | No | No |
| Needs an account | Sometimes | Check the listing | Usually | No |
Where Surv sits
Surv is an offline reference and field tool: guides, kit lists and tools kept together on the iPhone so they are there without a connection.
The App Store listing states that no account is required, and declares 44 app languages, which matters when the person who needs the information is not the person who installed the app.
What Surv does not do
It does not issue alerts, does not replace your national emergency service, and does not know what is happening where you are. For warnings, the official channel of your country is the reference and always will be.
It also cannot update itself without a connection. Content stored offline is content frozen at the moment you last opened the app with a signal, which is a limit worth understanding rather than discovering.
Questions
Which preparedness app works without internet?
Offline reference guides do, by design, because their content is stored on the device. Alert apps do not, because receiving a warning requires a connection. Test any app in airplane mode before you rely on it.
Can an app replace official emergency alerts?
No. Official warnings come from your national system. An offline guide holds reference material; it does not know what is happening around you.
What should I keep on paper?
Anything you would need with a dead battery: addresses, phone numbers and meeting points. Ready.gov recommends keeping information that does not depend on power.
Further reading
Guides
Prepare your phone to be useful when the network is not there
What survives a network outage, why text beats calls when everyone is dialling, how to keep documents readable offline, and how to make a phone last when there is nothing to charge it with.
An emergency kit inventory you will actually maintain
Why kits fail at maintenance rather than at assembly, how to build a list by walking through the box, what to record for each item, and how to run an annual review that takes under an hour.
A home emergency kit: the Ready.gov list, explained
What the United States government actually recommends storing, how much water and food, how to treat suspicious water, what to do when the power goes out, and how to keep the kit current.
What to put in a go-bag: an evacuation checklist
What an evacuation go-bag should hold, using the Red Cross and Ready.gov lists: water, food, medicines, documents, cash, and what each person adds.
How to purify water in an emergency: boil or disinfect
The EPA’s exact steps for boiling water and disinfecting it with unscented bleach, what these methods cannot remove, and how to store treated water.
Power outage checklist: before, during and after
What to prepare before a blackout, how long food stays safe, generator and carbon monoxide rules, and medical devices, from Ready.gov and the Red Cross.
How to use a compass: bearings, maps and declination
The parts of a baseplate compass, how to take and follow a bearing, orient a map, correct for magnetic declination, and avoid readings disturbed by metal.
First aid kit checklist: what the Red Cross recommends
The American Red Cross list for a family first aid kit, item by item, plus personal medicines, where to keep kits, checking expiry dates and getting trained.
How to prepare for an earthquake: Drop, Cover, Hold On
How to secure your home, what to do during the shaking with Drop, Cover, and Hold On, and what to check afterwards, from Ready.gov, ShakeOut and the Red Cross.
What to keep in an offline emergency kit, starting with your phone
A practical checklist for power, information, contacts and basic supplies when networks or electricity are unreliable.
Wildfire evacuation checklist you can prepare in an hour
What Ready.gov asks you to have before a wildfire warning, how to split the list between go-bag, car and house, and why the plan must work with the network down.
Heat wave checklist: staying safe when the power fails
How to prepare a home for extreme heat, what to do when the air conditioning stops, and the warning signs of heat exhaustion and heatstroke to watch for.