Fraud tied to fake identities and deepfake voices surged 700% in the first quarter of 2025 by most industry counts, and the phone is where it lands. AI voice cloning has turned “your grandkid needs bail money” from a Nigerian-prince joke into a real call your parents can be tricked by. Modern scam-call apps do two things worth paying for: they cross-reference incoming numbers against a shared spam database, and the best of them now flag likely AI voice patterns after you answer.
We tested seven Android scam call apps on the same handset for four weeks, with a mix of US, UK, and EU numbers.
What to look for in a scam call detection app
- Real-time caller ID lookup against a spam database.
- Local caller ID that does not upload your entire contact book.
- Blocking rules by prefix, country, or list.
- Voicemail transcription so you can see who called without listening.
- AI voice detection during or after the call.
- No-logs policy or a clear data retention timeline.
- Support for silencing “unknown callers” without breaking legitimate ones.
Quick comparison
| App | Best for | Platforms | Free plan | Starting price/mo | Rating |
|---|---|---|---|---|---|
| Should I Answer? | Privacy-first free option | Android | Full free | Free | 4.5 on Play Store |
| Truecaller | Largest global database | Android, iOS | Free with ads | Premium from around $2.99 | 4.4 on Play Store |
| Hiya | Carrier-grade detection | Android, iOS | Free basic tier | Premium from around $3.99 | 4.4 on Play Store |
| RoboKiller | AI answer bots | Android, iOS | 7-day trial | From around $4.99 | 4.4 on Play Store |
| Whoscall | Asia-first coverage | Android, iOS | Full free with ads | Premium from around $2.90 | 4.5 on Play Store |
| YouMail | Voicemail-first | Android, iOS | Free with ads | Plus from around $3.99 | 4.5 on Play Store |
| Nomorobo | Landline plus mobile | Android, iOS | 30-day trial | From around $1.99 per line | 4.3 on Play Store |
The apps
1. Should I Answer?, best privacy-first free option
Should I Answer? by Mister Group runs entirely on-device with an offline spam database you download once. Nothing about incoming numbers gets uploaded, and there is no upload of your contact book at any point. The database updates every week or so.
Where it falls short: The database is smaller than Truecaller’s. Fewer regional carriers covered outside Central Europe.
Pricing:
- Free forever.
- No paid tier, no ads.
Platforms: Android.
Bottom line: The first pick if privacy matters and you live in Europe. Combine with Truecaller only if the database gap becomes noticeable.
2. Truecaller, best global coverage
Truecaller has the largest crowd-sourced spam database of any app in this list, hundreds of millions of active users tagging numbers globally. Caller ID for unknown numbers is close to instant, and the app now offers an “AI voice detected” flag after suspicious calls.
Where it falls short: Historically criticized for aggressive contact-syncing defaults. Recent versions let you opt out but the initial onboarding still nudges you toward sharing.
Pricing:
- Free with ads.
- Premium from around $2.99 per month removes ads and adds spam recording.
Platforms: Android, iOS.
Bottom line: The biggest database in the game. Read the privacy defaults carefully during setup.
3. Hiya, best carrier-grade detection
Hiya powers the built-in spam detection on Samsung and AT&T phones, so many people use the underlying service without realizing it. The standalone app adds more granular blocking and shared user reports on top. Coverage in the US and UK is strong.
Where it falls short: Weaker in Latin America and Southeast Asia. Some blocking rules require a subscription.
Pricing:
- Free basic caller ID and reverse lookup.
- Premium from around $3.99 per month or $24.99 per year for full blocking.
Platforms: Android, iOS.
Bottom line: Solid pick in North America and the UK, especially on Samsung phones that already use Hiya under the hood.
4. RoboKiller, best AI answer bots
RoboKiller is the only app in this list that actively wastes scammers’ time. Its Answer Bots pick up flagged calls and keep the scammer talking to a scripted persona while you get on with your day. The recorded calls are shared with the community for later signature matching.
Where it falls short: Costs more than most alternatives. Answer Bots occasionally trigger on legitimate cold calls.
Pricing:
- Free: 7-day trial.
- Paid: From around $4.99 per month or $39.99 per year.
Platforms: Android, iOS.
Bottom line: For anyone who gets multiple scam calls a day and wants active revenge.
5. Whoscall, best Asia-first coverage
Whoscall by Gogolook is the household name for caller ID in Taiwan, Japan, and much of Southeast Asia. Its database of scam numbers in Chinese, Japanese, and Thai routes rivals what Truecaller has in Latin American ones. Free tier is very generous with only mild ads.
Where it falls short: North American number coverage is decent but not on par with Hiya or Truecaller. Offline mode requires a paid tier.
Pricing:
- Free with ads.
- Premium from around $2.90 per month for offline mode and ad removal.
Platforms: Android, iOS.
Bottom line: The first pick for anyone based in Asia or who receives regular calls from Asian numbers.
6. YouMail, best voicemail-first
YouMail treats voicemail as the primary interface. Instead of blocking calls outright, it lets calls ring, sends flagged ones to a visual voicemail box, and transcribes them. You skim, you delete, you get on with the day.
Where it falls short: Not the fastest for real-time blocking. Requires setup with your carrier for full visual voicemail replacement.
Pricing:
- Free with ads.
- Plus from around $3.99 per month, Pro around $8.99 for more storage and transcription.
Platforms: Android, iOS.
Bottom line: The right pick if you never answer unknown calls but still want to know who tried.
7. Nomorobo, best per-line pricing
Nomorobo started on landlines and expanded to mobile. Its per-line pricing is the friendliest for households running multiple lines. Focus is on robocall blocking rather than caller ID.
Where it falls short: Fewer features than the flagship apps. Interface feels dated.
Pricing:
- Free: 30-day trial.
- Paid: From around $1.99 per line per month.
Platforms: Android, iOS.
Bottom line: Cheapest per-line pick for households with several phones.
How to pick the right one
- If you want free and privacy-first: Should I Answer?.
- If you want the biggest global database: Truecaller.
- If you are on Samsung or in North America: Hiya.
- If you want to actively troll scammers: RoboKiller.
- If you receive calls from Asia: Whoscall.
- If you never answer unknown calls but want to know who called: YouMail.
- If you run multiple lines in a household: Nomorobo.
FAQ
What is the best free scam call app for Android?
Should I Answer? on F-Droid is the cleanest fully free option, no ads, offline database, no contact upload. Whoscall and Truecaller offer generous free tiers if you want a larger database.
Do scam call apps work against AI voice cloning?
The strongest apps (Truecaller, Hiya) now include AI voice pattern detection that flags suspicious calls in progress or after the fact. Detection is not perfect, especially against high-quality cloned voices. The best defense remains a codeword shared in advance with family.
Can these apps block calls without asking permission?
Android requires apps to request Call Screening permission before they can auto-block. All seven apps use this permission legally. If a call app blocks without asking, uninstall it.
Do they share my contacts with the developer?
Truecaller and Whoscall have historically pushed contact upload. Recent Play Store policy changes require clear consent. Should I Answer? and Nomorobo do not require contact upload at all.
What about spam text messages?
Truecaller, Hiya, and Whoscall all include SMS spam filtering on Android. Google Messages also has built-in spam detection that runs on-device, so many users do not need a separate SMS filter.
