It feels as if spam calls have been part and parcel of owning a mobile phone since the technology came into existence.
Nowadays, however, there's a multitude of apps that can help mitigate this problem – but many of them have problematic privacy policies and checkered pasts when it comes to user data. In this article, we list the best call blocking apps in 2021 and list some you should avoid, so you can get rid of spam calls once and for all.
The best call blocking apps in 2021
Here's a quick look at the best call blocker apps you can find on the Google Play and Apple App Store. A much more detailed analysis can be found further down in this article, but here's a brief rundown of our top picks:
- Should I Answer? - The best call blocking app around. It's effective, privacy conscious alternative to the most popular call blockers, not collecting any private data.
- WideProtect - an excellent call blocking app that is easy-to-use that doesn't collect any personalised data.
The best call blocking apps | In-depth analysis
All the providers in this article have been chosen because they pledge to protect their users' privacy whilst still providing a useful service, standing in stark contrast to some of the most popular call blockers available.
Wideprotect is an app made by independent developer Valerii Andrusyk, who designed it such that it never extracts personal data from your device - in fact, it doesn't collect any at all. There is no user registration and the app only works locally on mobile phones. Unpersonalised data like the device model is collected, but this is just for Wideprotect's analytics system and cannot be used to identify you. We contacted Valerii to confirm the app's privacy credentials, and he told ProPrivacy that the app does not even require customers' phone numbers to function.
Wideprotect can block up to 70 million numbers and offers SMS filtering capabilities, and you can even purchase extra call blocker extensions within the app. The interface is really user-friendly and the developer responded quickly and helpfully to questions about the app, which is a great sign. It's presently only available for iPhone users, so if you own one, check it out – it's only $2.99 to download.
Other popular call blocker apps
Is Hiya safe to use?
Hiya is one of the most popular call blockers around and has a number of impressive features as well as a large database. AT&T, and T-Mobile all use Hiya's call-blocking infrastructure and database and they have a partnership with Samsung. Although the app has thousands upon thousands of positive reviews, The NCC's Dan Hastings revealed around 18 months ago that Hiya sent data about users to analytics companies before a privacy agreement was even displayed to them. When these claims were made by Cnet and TechCrunch in 2019, the company said:
While it is true that Hiya currently sends some basic device data to third-party services upon opening the app (a standard industry practice in compliance with Apple's guidelines), that does not and has never included phone numbers or any Personally Identifiable Information (PII)."
Is Whoscall safe to use?
Whoscall has the largest spam call database in East Asia and over 80 million worldwide downloads. Whoscall says it will never share unencrypted data and has independently reviewed and awarded ISO 20071 security certification, one of the most widely-used standards for information security.
It does collect your user data and makes you upload your contact list, but claims to use 'de-identification technology' to convert it into non-identifiable information, and informs customers it employs two layers of encryption because Whoscall is 'liable for the security of all user data'. However, similarly to Hiya, they also say information is de-identified, but as was covered, this isn't an irreversible process. Any suggestions that your data can be 'de-identified' should be treated with caution, regardless of the company making them.
Is PrivacyStar safe to use?
Privacy Star is made by First Orion, a scam protection and call management software company with hundreds of employees. PrivacyStar has a number of features, including the ability to assign Caller IDs to unknown numbers and perform a reverse lookup on those dialing into your phone. There's also a pretty unique tool called CallerYD (Android only), which not only tells you who is calling, but why.
Furthermore, it seems like a lot of previously satisfied customers on the Google Play Store have had some issues with a recent update, although PrivacyStar's customer support team has responded politely to the negative comments, asking users to detail their problems in emails and assuring customers that they are currently working to fix the issues.
Is Call Control safe to use?
Call Control, like many of the call blockers, uses a community-based feedback mechanism to identify spam numbers and reliably block them for its more than 12 million users. Along with blocking incoming spam calls, the app prohibits fraudsters leave irritating voicemail messages and lets you create your own personal blacklist. Call Control can be customized to block specific area codes, something it can also do for foreign numbers.
Call Control also says that, when you use the service, its "servers automatically record certain information that your web browser sends whenever you visit any website" which includes, amongst other things, "web requests", "pages viewed" and "the amount of time spent on certain pages" tracked by "one or more cookies that may uniquely identify your browser."
Spam calls and scam calls
Every day, millions of cold calls are made by salesman, technicians, and scammers across the world, each operator with their own pathway to profit.
Spam calls are usually defined as unprompted and unwanted communications from salespeople and marketers looking to sell you some sort of product or service. They shoot from the hip; it doesn't matter how poor the product or service they're offering is, the more individuals they manage to contact, the more likely that they will make a sale. Although irritating – especially when it's a robotic voice – the product and sales process is legitimate. They could even be from a company you've previously done business with.
Scam calls, on the other hand, involve malicious actors intentionally looking to con you out of your money or sensitive, personal information via a phone call. Over the phone, this usually involves the fraudster trying to sell those who pick up products – but these sorts of calls can also involve made-up threats of fines, arrest, and imprisonment to intimidate victims.
Call blocker app Truecaller analyzed 145 billion calls in 2020 and found that spam calls rose globally by around 159%. This is likely due to the fact that spammers are looking to take advantage of the uncertainties plaguing almost every nation on earth.
Brazil seems to be a hotspot for spam callers, with a 9% rise on last year's total and the overall highest number of spam calls, over half of which are outright scams.
The US, on the other hand, saw a 56% increase on last year's numbers – and 55% of recipients of spam calls got one that was Covid-related. Between April 2019 and April 2020, US citizens lost upwards of $19.7 billion to fraudsters via scam calls, a cruel illustration of the financial impact the practice is responsible for.
There has also been a huge increase in Europe – countries like the UK, Spain, Ukraine, Greece, Belgium, and several others have entered the 'top 20' countries for spam calls despite being nowhere near it last year.
Call blocker apps are a privacy minefield
Call blocker apps do exactly what they say on the tin: they block calls from unfamiliar or unusual numbers and allow you to take back control of your mobile phone and who exactly can come into your space. As you can probably imagine, this sort of app isn't just handy when it comes to blocking spam and scam calls, but any unwanted correspondence at all from your personal life.
However, the problem with many call blocker apps – including some of the most widely downloaded ones – is that they crowdsource their databases for their service to work, something which often requires customer's contacts to be uploaded to servers. Where your contacts – or indeed your phone number and other personal information – end up is not always clear. The privacy policies of some of the most widely used call blockers have worried security experts:
I carefully read through these policies, and it was disheartening, if not entirely surprising. Even products specifically designed to prevent spam invade user privacy.
Many call blockers available on the Apple and Google Play stores rely on advertising to get by; many are free. A lot of others claim to use third-party entities to deliver certain app functions. This leads to a data-sharing relationship with third parties organizations that makes some users uncomfortable, particularly those searching for a call-blocking app who likely feel their privacy is already at risk. However, this is how many apps, call blockers and others, make their money whilst remaining free to download.
Call blocker apps you should probably avoid
Although call blocker apps can be a powerful tool to help you reclaim your privacy, not all of them operate with customer security in mind. Some of the most recognizable names in the industry have been exposed for having incredibly poor data practices. We cannot recommend these providers in good faith due to either how they operate and their recent history of data practices.
Truecaller, in terms of blocking calls, is a real sector leader and produces detailed reports on the state of the spam call landscape regularly. This is made possible by its huge database of numbers collected from over 10 billion processed calls; you can even check through it to see exactly which company is attempting to get a hold of you. Truecaller has tens of thousands of reviews online and over 200 million active users.
However, Truecaller has to access your phone contacts to work. The company claims they 'do not upload phonebooks to make them searchable to the public', and instead get their numbers from community suggestions and 'partnerships with various phone directory providers'. Truecaller is one of those call blocking apps that relies on a crowdsourcing technique to build its database. However, there have been several reports that they upload entire phonebooks to their servers, but Truecaller says this only happens when Enhanced Search is enabled. Either way, it seems like you end up with people on Truecaller's books who haven't been asked if they want to be. Speaking on Apple and Google's policies that bar apps from uploading phonebooks to servers three years ago, their then marketing director said:
We are 100% compliant with these policies. We do not upload the phone book from users who download the app from Google Play Store and Apple App Store
However, since then, there have been reports Truecaller has allegedly jeopardized the work and welfare of journalists, whilst India's Economic Times, the second-most read business paper in the world, reported in 2019 that Truecaller user data was found for sale on internet forums.
Although Trapcall has since suggested this is only to 'power internal analytics', the fact this wasn't previously stated isn't assuring. In response, Trapcall said in a statement that it "only shares phone numbers with service providers who power our internal analytics and app messaging platforms. Additionally, service providers are prohibited from using TrapCall data for their own or any other purpose."
Built-in call blockers
The majority of Apple and Android devices that have the capacity to receive calls afford users the ability to add numbers to a blocked list and have modes that can bar calls from everyone except a select few contacts. Further, Apple has a setting you can turn on that reroutes all calls from non-contacts straight to voicemail.
However, for some, this might actually be too stringent for some people; if you're waiting to hear back from a prospective employer or the doctors, you probably don't want all calls blocked. But then again, you could always temporarily modify these settings.
Well-designed call blocker apps are often better at location-sensitive blocking and have larger dedicated spam directories – but as has been discussed, these often come alongside an unpalatable compromise of user privacy. They do tend to be the more feature-rich option than a built-in call-blocker with higher customizability, but this isn't necessarily worth it.
Are 'do not dial' registers obsolete?
Years ago, the general rule of thumb for those who wanted to avoid unwarranted spam calls was to sign up to a given country or region's 'do not dial' register, which businesses that incorporate cold calling into their sales strategies sign up to.
In the US this is called the 'Do Not Call Registry' whereas in the UK the organization that compiles the list is called the Telephone Preference Service. Other nations will have different names for their register.
But the world has changed. A lot of spam calls now come from outside of the country that the recipients reside in, and the spammers are thus not beholden to any of the domestic laws enforced by the government of the people they're calling. Depending on where you live, your country's do not dial registers might not stop:
- Calls from companies you've done business with
- Political advertisements and other similar content
- Charity cold-calling and other third-sector calls
- Calls that are classified as 'informational'
Besides, what if one of the companies using a 'do not dial' database has a weak security parameter? One data breach could mean the list is compromised and you could actually end up receiving more calls.
All things considered, it's now better to take responsibility for protecting yourself from spammers rather than handing your phone number over to a registry that can no longer guarantee to be that helpful.
Check out our how to block text messages guide for more information about avoiding spam.
If you want the most robust defense possible when it comes to unwanted calls without compromising your privacy, then a third-party call blocker app recommended in this article is the best way to go. Although the two suggested have slightly different features, they're both there to give you maximal control over your incoming calls.
Remember, there are spam and scam messages designed to reach users across all sorts of mediums – be that email, websites, or phone calls – so make sure you check out the services designed to give you more control over other mediums of communication. But we'd never advise compromising your own privacy to block a few calls, so be sure to check service privacy policies before signing up. Here's a final reminder of the services featured here today: