Corta Spam
Corta Spam: A rule-heavy, on-device Android blocker for precise call screening before ringing. Ranked #25 of 40 in Spam Call Blocking Apps by our editors (6.4/10); pricing: Free plan; best for rule-heavy open-source Android call screening.
At a glance
- Editor score6.4 / 10
- PricingFree plan
- Best forRule-heavy open-source Android call screening
- Free planYes
- Paid fromFree
- Facts checked21 Sep 2026
Where it wins
- Screens calls before the phone rings using detailed local rules
- Supports country, wildcard, repeat-caller, quiet-hours, and list controls
- Open-source, ad-free, tracker-free, and designed for on-device data handling
Where it doesn't
- Android is the usable platform for call blocking
- Does not include community spam reports
- Auto-responder functionality is experimental
Our verdict on Corta Spam
Corta Spam is an open-source Android app for screening incoming calls before the phone rings. It suits people who want detailed local control over unwanted calls rather than a system based on community reports. Rules can use manual blocklists and allowlists, prefixes, suffixes, wildcards, country codes, repeat-caller attempt thresholds, and quiet-hours schedules. The app also includes caller identification on the call screen and a bundled on-device spam list.
Its standout strength is the depth of its rule engine. Corta Spam can block or allow calls according to several types of number and caller behavior, giving users more control than a simple blocklist. It also includes an experimental auto-responder with a custom greeting, plus call logs, statistics, and JSON backup and restore. The open-source design, ad-free and tracker-free positioning, and on-device data handling make it a focused option for users who prefer local processing and configurable policies.
Platform fit is the main boundary. Android is the usable platform for call blocking, while the iOS shell can build and run but does not yet provide iOS call blocking. The app also lacks community reports, so it is less suited to people who want crowdsourced identification of known nuisance numbers. Choose Corta Spam for Android-based, rule-heavy screening with local controls; consider an alternative if iOS support or community-powered spam intelligence is central to the buying decision.
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Corta Spam pricing
Corta Spam fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Robocall blocking | Not verified |
| Caller ID | Yes |
| Call screening | Yes |
| Community reports | No |
| Supported platforms | Android |
| Blocked-number limit | Not verified |
| Deployment | Mobile |
| Platforms | Android |
| Support | Docs |
| Built for | Solo (editorial estimate) |
| Pricing | Free plan |
| Website | github.com |
| Facts checked | 21 Sep 2026 |
Alternatives to Corta Spam
- TruecallerA broad caller ID and spam protection app for iOS and Android.9.3
- T-Mobile Scam ShieldA free core service for T-Mobile customers, with paid call-management upgrades.9.1
- Verizon Call FilterA practical Verizon-integrated blocker with useful free protection and paid caller ID.9.0
See all Corta Spam alternatives →
Also Ranked In
Corta Spam is ranked in 2 of our directories.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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