Professional Phone Validation API for Developers

“Phone-Check.app transformed our SMS marketing. We reduced SMS delivery failures from 12% to 1.8% in just one month. The real-time validation catches formatting errors instantly, and the VoIP number detection saved us from thousands of fake signups. ROI was positive within 2 weeks.”

“The accuracy is incredible - 99.6% as advertised across 232 countries. We validate 2M+ phone numbers monthly for our e-commerce platform. Invalid registrations dropped from 15% to 0.8%. The format corrections alone recover 7% of phone numbers. Customer acquisition cost decreased by 23%.”

“VoIP number detection is a game-changer. We blocked 250,000+ VoIP numbers that were creating fake trial accounts. Fraud attempts dropped by 87%, saving us $40K monthly. The API is lightning fast - 35ms average response time never slows our signup flow.”

“Integration took 5 minutes with their excellent documentation. The bulk validation processed our 500K phone number list in under an hour, identifying 18% invalid numbers we were paying to message. Switching from our previous provider saved us 65% while getting better accuracy.”

“HLR verification without sending SMS is brilliant. We validate B2B leads in real-time, improving sales efficiency by 40%. The location data helps us personalize outreach. Our SMS delivery rate improved from 73% to 96% in 3 months.”

“The API handles our global SMS campaigns across 232 countries flawlessly. VoIP number detection prevents us from hitting fraud traps. We process 10M validations monthly with zero downtime. Best phone validation service we've used in 10 years.”

“Real-time form validation increased our conversion rate by 28%. Users love the instant format corrections and country detection. The JavaScript SDK was plug-and-play with our React forms. SMS delivery rate on welcome messages went from 92% to 99.7%.”

“Bulk validation saved our SMS reputation. We inherited a list with 35% invalid phone numbers. Phone-check.app cleaned it in 2 hours, preventing carrier blocking. The detailed risk scoring helps us segment our sends. Worth every penny.”

“The phone validation service let us test thoroughly before committing. Now we validate 100K+ phone numbers monthly. The webhook integration keeps our CRM always clean. Support team is incredibly responsive and helpful.”

“We validate every phone number at checkout, reducing payment fraud by 73%. The API speed (35ms) doesn't impact checkout flow. Risk scoring identifies suspicious patterns. Chargeback losses dropped from $15K to $4K monthly.”

“Phone validation is now part of our data quality pipeline. We validate before every campaign, maintaining >98% delivery rate. The API reliability is exceptional - 99.99% uptime over 18 months. Integrates perfectly with our marketing stack.”

“The pay-as-you-go credits are perfect for our seasonal business. We buy credits during peak times without monthly commitments. Validation accuracy helped us achieve the highest SMS engagement rates in our industry. Fantastic service!”