A Developer’s Guide to SMS Testing with Non-VoIP Temporary Numbers

When you’re building features that rely on SMS, you’ll probably find that the testing process becomes a major bottleneck.

That’s where you can benefit from using non-VoIP temporary numbers. These behave like real mobile numbers, but their major benefit is that they don’t require you to set up physical devices for testing purposes or commit to long-term contracts.

If you’re thinking of using non-VoIP temporary numbers to test your next project, keep reading—we’re sharing everything you’ll want to know in this guide.

Why Should You Use Non-VoIP Numbers For Testing?

If you’re still wondering why you should specifically use non-VoIP numbers for your project testing, or even how they’re different than VoIP numbers, here’s what you should be aware of.

First, a quick comparison: VoIP numbers are tied to a fixed location, while non-VoIP numbers aren’t (they can be used anywhere, provided you have an internet connection).

A lot of websites and services block VoIP numbers because they can be easily changed, so they can’t be identified with 100% accuracy. If you try to sign up or verify an account with a VoIP number, you might never receive the SMS at all.

Non-VoIP numbers are different: they’re treated as standard wireless lines by verification systems, so they’re much more reliable for end-to-end SMS testing.

You obviously need to replicate the real user experience when you’re testing SMS-based authentication or messaging flows. If your test number gets blocked or flagged, you can’t trust your data. Using non-VoIP numbers for your testing will give you better results.

The Appeal of Temporary Numbers in Particular

When you’re conducting QA testing or rolling out new features, you probably don’t need (or want) to sign up for a long-term contract with your testing numbers. And that’s the key appeal of using a service that provides temporary non-VoIP numbers, like https://www.smspool.net/.

You can get fast access to a number, complete your testing, and then discard it. There’s no need to manage a pool of long-term test phones or SIM cards. Instead, you can pull an online temporary number on demand—the much more convenient option.

Make Sure to Rotate Your Numbers

One way to avoid getting blocked when you’re testing over an extended period of time is by rotating your numbers. The good news is that most providers offer this as a built-in option.

Essentially, you want to avoid using the same number too often, which can trigger the receiving platform to initiate spam protection. That means you can keep your sign-up or login flows behaving the way they should for new users.

What to Do With A Used Number

When you’re finished using a number in your testing, it’s best to remove any data tied to it, clearing out any SMS codes or verification tokens your system stores. Doing this will help you avoid collisions in any of your future tests, as well as keeping your test environment predictable.

You’ll also want to label your test traffic clearly in your logs, which will make it a lot easier to isolate issues and compare your production vs test results.