Cost analysis · verified July 2026
Everyone meters your minutes. Stonekept meters bytes.
Voice-AI apps charge by the minute, by the recording, or by the seat, because your audio runs on their servers. Stonekept runs capture, transcription, and memory extraction on the device you already own, so a recording costs nothing to make. Here is the whole field, priced per 30-minute meeting.
The price of one meeting
Cost per 30-minute meeting
Each product's main individual paid tier. Plans that include unlimited recording are shown at two meetings a workday, about 40 a month, so they line up against the capped plans. Their real cost per meeting only falls further as you record more.
Scale runs $0 to $5 per 30-minute meeting; each bar is labeled with its exact cost. Sonix is pay-as-you-go, the rest are monthly subscriptions. Several plans are cheaper billed annually (Otter, Plaud and Voicenotes Pro drop to about $0.21, Notta to $0.14).
The field charges 15 to 75 cents for a 30-minute meeting, and Sonix wants five dollars. Stonekept charges nothing to make the recording and about an eighth of a cent a year to keep it.
The free tier
How many recordings you actually get for free
Free tiers look generous until you read the unit. Several give you a fixed handful for the entire life of the account, not per month, and one caps a single recording so short that a real meeting will not fit.
The math behind $0
Why it costs Stonekept almost nothing
Audio is the only line item with a price, and it is tiny. The memories, transcripts, and knowledge graph are a rounding error next to the audio itself.
Stored audio is Opus mono at 32 kbps, now encoded at a 48 kHz sample rate after a recent quality fix that made it crisper at no extra size. Cloudflare R2 storage runs $0.015 per gigabyte-month with free downloads, so cost tracks bytes, and bytes are cheap. There is no monthly cap: local capture is unlimited on every tier, and cloud backup is bound only by the size of your bucket.
The numbers
Every tier, in full
| Product · tier | Metered by | 30-min mtgs/mo | $ / meeting |
|---|---|---|---|
| Sonix · Pay-as-you-go ($10/hr) | per audio hour | buy as needed | $5.00 |
| Fellow · Team $11/mo | recording count (10/mo) | 10 | $1.10 |
| tl;dv · Pro $29/mo | flat per seat | unlimited | $0.73 |
| Avoma · Startup $29/mo | flat per seat | unlimited | $0.73 |
| Fathom · Premium $20/mo | flat per seat | unlimited | $0.50 |
| Omi · Unlimited $19/mo | flat, + $89 device | unlimited | $0.48 |
| Bee · $19/mo | flat, + $50 device | unlimited | $0.48 |
| Plaud · Pro $17.99/mo | 1,200 min/mo, + $159 device | 40 | $0.45 |
| Fireflies · Pro $18/mo | flat per seat | unlimited | $0.45 |
| Otter.ai · Pro $16.99/mo | 1,200 min/user/mo | 40 | $0.42 |
| Voicenotes · Pro $14.99/mo | flat per account | unlimited | $0.37 |
| Granola · Business $14/mo | flat per seat | unlimited | $0.35 |
| Mem · Pro $12/mo | notes + chats (no audio) | n/a (text) | ~$0.30* |
| Notta · Pro $13.99/mo | 1,800 min/mo | 60 | $0.23 |
| AudioPen · Prime $99/yr | one-time pass, 15-min cap | unlimited notes | $0.21 |
| Cleft · Plus $6.99/mo | 30-min per-recording cap | unlimited | $0.17 |
| Apple Voice Memos · free · built-in | on-device (nothing) | unlimited | $0.00 |
| Superwhisper · Pro $8.49/mo | on-device (nothing) | unlimited | ~$0 |
| Stonekept · Free · Sync · Pro | cloud storage bytes only | unlimited | $0.00 |
"Unlimited" plans are converted to a per-meeting figure at 40 meetings a month (two per workday) so they compare to the metered plans; record more and their per-meeting cost drops. Stonekept's figure is what you pay; its cost to serve is about $0.0001 a month in storage. Mem (*) is a text second-brain with no audio recorder, so its per-meeting figure is notional.