Founder builds on-device deepfake detection after scam call

About two years ago, Tarini Padmanabhuni’s grandfather believed he was talking to his brother on the phone. The voice said he’d been kidnapped and that the only way to get him back was to pay a ransom. Her grandfather paid, only to learn later that his brother had been somewhere else entirely, with no idea any of it was happening — the voice was a deepfake, an AI-generated imitation. “What stayed with me wasn’t the money,” Padmanabhuni says of the incident. “It was that he had no way of telling.”

Today, Padmanabhuni’s San Francisco-based company, DetectifAI, aims to make sure others aren’t fooled the same way. It’s a big and growing problem: according to the FBI, Americans lost close to $900 million to AI-driven scams last year, up 24% from 2024, and people 60 and older lost twice as much as those aged 50 to 59. There’s no shortage of competition in deepfake voice detection, including Reality Defender, Pindrop, Resemble AI, Microsoft Azure AI Content Safety, and Nuance (which Microsoft also owns). But Padmanabhuni argues today’s detection products run in the cloud on remote servers, so phone makers can’t build them directly into devices, leaving the person being targeted with little defense in the moment.

Rather than shrinking large cloud models to fit on a phone, DetectifAI designs compact AI models from the start that are small enough to run inside a smartphone’s operating system, delivering an instant verdict on whether a voice is AI-generated during calls, voice messages, and other audio, without the audio ever leaving the device. The startup is selling first to phone manufacturers, licensing its software so detection can ship as a built-in feature — comparing the opportunity to AT&T’s exclusive role in the original iPhone launch, with the first phone maker to ship DetectifAI gaining an edge and deepfake detection becoming a standard spec, like camera resolution. A secondary revenue stream comes from licensing the technology to businesses and fraud-prevention firms.

DetectifAI already has early revenue, according to Padmanabhuni, handling more than 100,000 calls a month for financial institutions in India — calls placed by AI voice agents that handle debt collection and loan follow-ups, with deepfake detection and speaker verification on every call. She declined to name customers, citing confidentiality agreements. The startup has raised a small seed round from investors Josh Constine, a former TechCrunch editor, and Manohar Kamath, a principal at consulting firm KM Growth.

Why it matters

As voice cloning gets cheap enough to fool a grandfather, DetectifAI is betting that deepfake detection becomes infrastructure baked into the phone itself rather than a cloud service victims never think to check.