Privacy9 min read

Local vs Cloud Speech-to-Text: Privacy Comparison

Compare local and cloud-based speech-to-text processing. Understand the privacy, security, speed, and accuracy trade-offs for dictation on Mac.

Scrybapp

Scrybapp Team

The Fundamental Choice: Where Does Your Voice Go?

When you use a speech-to-text tool, your voice audio must be processed by an AI model to convert it to text. The critical question is: where does that processing happen? The answer has profound implications for your privacy, security, and data sovereignty. There are two approaches: cloud processing (your audio is sent to remote servers) and local processing (everything happens on your device).

How Cloud Speech-to-Text Works

When you use a cloud-based dictation tool like Wispr Flow, Google Voice Typing, or Microsoft Dictate:

  1. Your microphone captures your voice
  2. The audio is compressed and transmitted over the internet to the provider's servers
  3. The audio is processed by AI models on remote hardware
  4. The resulting text is sent back to your device
  5. The audio may be stored, logged, or used for model training

How Local Speech-to-Text Works

When you use a local dictation tool like Scrybapp:

  1. Your microphone captures your voice
  2. The audio is processed by Whisper AI running on your Mac's hardware
  3. The resulting text appears in your application
  4. No audio or text data ever leaves your device

Privacy Comparison

Data Exposure

Cloud processing exposes your voice data to multiple risks:

  • Transmission interception — Data in transit can theoretically be intercepted
  • Server storage — Many providers store audio for quality improvement
  • Employee access — Provider employees may access audio for quality review or model training
  • Data breaches — Cloud providers are cyberattack targets
  • Legal compulsion — Governments can compel cloud providers to hand over data
  • Terms of service changes — Providers can change data policies retroactively

Local processing eliminates all of these risks. When your audio never leaves your Mac, there is nothing to intercept, store, access, breach, compel, or repurpose.

Who Sees Your Content?

Consider what you dictate: emails containing business strategies, medical notes with patient information, legal documents with privileged content, personal journal entries, and private communications. With cloud processing, all of this passes through a third party. With local processing, it stays on your Mac.

Security Comparison

Attack Surface

Cloud processing introduces a large attack surface: internet transmission, API servers, processing servers, storage systems. Local processing has a minimal attack surface: your Mac's hardware and the locally installed software.

Compliance

  • HIPAAMedical professionals must protect patient data. Local dictation avoids transmission entirely.
  • Attorney-client privilegeLawyers must protect privileged communications.
  • GDPR — Local processing keeps data in your jurisdiction.
  • FERPAEducators must protect student data.

Read our HIPAA dictation guide and privacy policy.

Speed and Reliability

Latency

Cloud dictation adds 500ms-2000ms of network latency. Local processing on Apple Silicon eliminates network latency entirely.

Reliability

Cloud dictation fails without internet. Local dictation works anywhere, anytime. See our offline dictation guide.

Accuracy Comparison

Historically, cloud had an accuracy advantage. That gap has closed:

  • Whisper Large (local) achieves accuracy competitive with the best cloud services
  • Whisper Medium (local) exceeds most cloud tools for general use
  • Apple Silicon optimization means local models run efficiently

See our accuracy benchmarks and Whisper model comparison.

Cost Comparison

AspectLocal (Scrybapp)Cloud (Typical)
PricingOne-time 39€$8-15/month
Year 1 Cost39€$96-180
Year 2+ Cost0€$96-180
5-Year Total39€$480-900

When Cloud Makes Sense

Cloud processing may be preferred when using very old hardware that cannot run AI models, when needing AI features beyond transcription (like text reformatting), or for extremely rare languages needing the very largest models. For the vast majority of Apple Silicon Mac users, local processing offers better privacy, comparable accuracy, lower cost, and greater reliability.

Our Recommendation

Scrybapp and local processing is the clear choice for privacy-conscious users. You get excellent accuracy, zero data exposure, offline capability, and no subscription costs. Download Scrybapp with 3 minutes of free transcription.

Related: best Mac dictation apps, Apple Silicon AI, offline dictation.

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