AI tool comparison
Gemini 3.1 Flash TTS vs Ghost Pepper
Which one should you ship with? Here is the side-by-side panel verdict, pricing read, reviewer split, and community vote comparison.
Voice & Audio
Gemini 3.1 Flash TTS
Google's new TTS API: 70 languages, 200+ audio tags, native multi-speaker
75%
Panel ship
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Community
Free
Entry
Gemini 3.1 Flash TTS is Google's new text-to-speech model, launched today on Google AI Studio and Vertex AI. It supports 70+ languages and introduces a natural-language audio tag system with 200+ expressivity controls — developers can describe delivery in plain English ("whisper conspiratorially", "warm and unhurried") and the model interprets those instructions at inference time. The model also supports native multi-speaker dialogue generation from a single prompt, outputting a conversation with distinct, consistent voices without requiring separate passes. All audio output is watermarked via Google's SynthID technology for provenance tracking. For developers building voice agents, podcasting tools, or multilingual apps, this is a meaningful upgrade over existing options. The audio tags approach in particular is a genuinely novel paradigm compared to prosody markup languages like SSML, and developer reception on X and HN has been strong — Simon Willison called out the expressivity controls as the standout feature.
Voice & Dictation
Ghost Pepper
Hold Control. Speak. Release. It types for you — all on-device.
75%
Panel ship
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Community
Free
Entry
Ghost Pepper is a macOS hold-to-talk dictation app that runs entirely on-device using Apple's WhisperKit for speech recognition and LLM.swift for smart cleanup. You hold the Control key to record, release to transcribe, and the transcribed text is automatically pasted into whatever app you're using. No cloud, no subscription, no data ever leaves your Mac. The "smart cleanup" feature is what sets it apart from basic Whisper wrappers: it uses a local language model to remove filler words, fix self-corrections in real time, and clean up stutters without altering your intent. Version 2.0.1, released April 6, brings improved accuracy and lower latency on Apple Silicon. It requires macOS 14+ and an Apple Silicon chip. Ghost Pepper hit the top of Hacker News' Show HN section on April 7 with 354 points and 164 comments — an unusually strong signal for a solo-dev open-source tool. The timing is notable: as commercial dictation tools like Wispr Flow move to paid-only models, Ghost Pepper offers a fully free, auditable alternative. It's MIT-licensed and available on GitHub.
Reviewer scorecard
“This replaces ElevenLabs for a lot of use cases — and at Google's pricing it's hard to argue against. The natural-language audio tags are the real unlock: instead of wrestling with SSML prosody markup, you just describe what you want. The multi-speaker output from a single prompt is going to save a ton of orchestration code in voice agent pipelines.”
“This is the dictation tool I've been waiting for. On-device, zero latency once warmed up, MIT license, and the LLM cleanup actually works. I replaced Wispr Flow with this in under 5 minutes. The Control-hold UX is more ergonomic than I expected.”
“It's Google — which means it could be deprecated in 18 months and replaced with Gemini 4 Flash TTS Pro Ultra. The audio tags sound creative but until there's a published spec for all 200+ of them, you're guessing at prompt-engineering your voice model. And SynthID watermarking is only as useful as the detection ecosystem, which is still nascent.”
“Apple Silicon only and macOS 14+ means a significant portion of Mac users are locked out. The 'smart cleanup' LLM adds another model to memory — not ideal if you're already running other local models. Also, no GUI means non-technical users won't touch it.”
“Natural-language expressivity control for TTS is a paradigm shift. When the model can interpret 'sound like you're delivering devastating news gently' without explicit prosody markup, we're entering an era where voice synthesis becomes genuinely directorial. The 70-language coverage plus SynthID watermarking points toward a future where synthesized voice is both globally expressive and auditably provenance-tracked.”
“Ghost Pepper is a preview of how computing will feel in 5 years: ambient voice input everywhere, zero latency, zero cloud dependency. The fact that a solo dev shipped this in Swift using WhisperKit and LLM.swift is a testament to how capable the Apple Neural Engine stack has become.”
“I've been paying for ElevenLabs and manually tweaking prosody to get the right delivery. The audio tag system here could cut that iteration time dramatically — describing the scene and letting the model interpret is so much more intuitive than sliders and SSML. Multi-speaker from a single prompt is going to be huge for podcast generators and explainer video tools.”
“I tried it during a writing session and the filler-word removal alone is worth it — my raw dictation comes out cleaner than when I type. The hold-to-talk model also means I'm never accidentally recording. Solid privacy story for journaling and creative work.”
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