Cheapest AI Voice API in 2026: Real Cost per Minute
Cartesia Sonic 4's $0.05 per 1,000 credits versus ElevenLabs' $0.167-$0.22 turned into real per-minute and per-project voiceover costs, with the math shown.
Cartesia Sonic 4 is the cheapest text-to-speech API worth using in 2026, at roughly $0.05 per 1,000 credits — about 3-4x cheaper than ElevenLabs' usage rate of $0.167–$0.22 per 1,000. Turned into real numbers: a 10-minute narration runs about $0.50 on Sonic 4 versus $1.50–$2.00 on ElevenLabs. A 100-video batch of one-minute clips runs about $5 versus $15–$20.
Per-1,000-credit pricing is meaningless until you know how many minutes of finished voiceover a thousand credits actually buys. Here's that conversion, shown, with the assumptions stated plainly so you can check them against your own script.
The short answer
- Cheapest per minute: Cartesia Sonic 4, at roughly $0.045–$0.05 per minute of narration.
- Most expensive of the two with published rates: ElevenLabs v3, at roughly $0.15–$0.20 per minute above its free quota.
- A 10-minute narration: ~$0.50 on Sonic 4 vs ~$1.50–$2.00 on ElevenLabs.
- A 100-video batch (1 min each): ~$5 on Sonic 4 vs ~$15–$20 on ElevenLabs.
- Hume Octave 2 and Deepgram don't publish a flat per-1,000 rate the way Cartesia and ElevenLabs do — budget them by requesting a quote or running a real test batch, not by assuming a number here.
- Cheapest isn't always right — see the decision rule at the bottom before you default to the lowest number.
The conversion, and the assumption behind it
Providers meter differently — credits, characters — so any per-minute figure requires an assumption about how much spoken audio a thousand units actually produces. This uses a standard voiceover pace: roughly 150 spoken words per minute, which comes out to about 900 characters including spaces — call it 900 units per minute as a clean planning number. That's a modeling assumption, not a number either provider publishes directly, so treat the per-minute figures below as planning estimates and confirm the exact metering with each provider before committing a large batch.
The pricing table
| Provider | Price per 1,000 | Estimated cost per minute* | 10-min narration | 100 × 1-min batch |
|---|---|---|---|---|
| Cartesia Sonic 4 | ~$0.05 | ~$0.045 | ~$0.45–$0.50 | ~$4.50–$5 |
| ElevenLabs v3 (above quota) | $0.167–$0.22 | ~$0.15–$0.20 | ~$1.50–$2.00 | ~$15–$20 |
| Hume Octave 2 | Not published | Not comparable the same way | Request a quote / test batch | Request a quote / test batch |
| Deepgram | Enterprise/contract | Not comparable the same way | Contract-based | Contract-based |
*Estimated at ~900 units per minute of spoken narration. Actual cost scales with your real script length and pacing, not this average.
What that actually means for two real jobs
A single 10-minute narration — an explainer, a course module, a long-form video voiceover — costs about 50 cents on Sonic 4 and $1.50–$2.00 on ElevenLabs. At this scale, the dollar difference is trivial either way; the decision should be made on quality and control needs, not price, because you're arguing over roughly a dollar.
A 100-video batch, at one minute of narration each — the shape of a daily short-form posting schedule run for about three months — costs roughly $5 on Sonic 4 versus $15–$20 on ElevenLabs. That's still not a large absolute number, but it's a real 3-4x multiplier, and it compounds further at genuine scale: a team generating narration for 1,000 videos a month is looking at roughly $50 versus $150–$200 — the gap that actually shows up on an invoice.
ElevenLabs' free tier (10,000 characters/month, roughly 11 minutes) and $49/month Pro plan change this math for steady, moderate usage — if your monthly narration volume fits inside a plan's included allowance, you're paying the flat subscription rate, not the per-1,000 overage rate used above. The overage math matters most once you're consistently exceeding plan limits or running bursty, unpredictable volume.
Why the cheaper option isn't automatically the right one
Cost per minute is one axis. It's not the only one, and defaulting to the cheapest API on every job is how a project ends up sounding wrong for the content even while coming in under budget.
The fuller decision rule, covered in more depth in the best text-to-speech API roundup: pick by latency need, expressiveness need, and empathy need first, and let price break the tie only when none of those bind. Cartesia Sonic 4 happens to win on latency and price simultaneously, which is why it's the default for most volume work. But a script that needs Hume Octave 2's emotional nuance or ElevenLabs' language and voice breadth is a case where the cheaper option produces a worse result, not just a cheaper one — and a bad read that has to be redone erases the savings fast.
Budgeting it inside a real pipeline
If your voiceover is headed into a published video rather than a standalone audio file, the more relevant cost isn't the raw per-1,000 API rate anyway — it's the credit cost of the whole pipeline: script to voice to video to captions to publish. Versely's AI text-to-speech tool runs on the same credit-based model as its video and captioning tools, so testing a script costs the same whether you're auditioning three takes or committing to a final one — which matters more for your actual budget than the underlying per-1,000 rate, since retakes are usually where content budgets quietly blow past estimates. For projects that also need a consistent cloned voice across a batch, AI voice cloning is worth pricing in as a one-time setup cost rather than a per-minute one.
FAQ
What's the cheapest AI voice API in 2026? Cartesia Sonic 4, at roughly $0.05 per 1,000 credits — about 3-4x cheaper than ElevenLabs' $0.167–$0.22 usage rate.
How much does a 10-minute voiceover actually cost? Roughly $0.45–$0.50 on Cartesia Sonic 4, and roughly $1.50–$2.00 on ElevenLabs above its free quota, using a standard ~150-words-per-minute narration pace.
How much would voiceover for 100 short videos cost? At one minute of narration per video, roughly $5 on Sonic 4 versus $15–$20 on ElevenLabs — a real gap at volume, though a small one in absolute dollars at this scale.
Are Hume Octave 2 and Deepgram cheaper or more expensive than Cartesia? Not directly comparable — neither publishes a flat per-1,000 consumer rate the way Cartesia and ElevenLabs do. Hume is usage/quote-based and Deepgram is typically contract-priced, which reflects who each is built for rather than a missing data point.
Is a subscription or credit-based pricing cheaper overall? It depends on your volume pattern. Steady usage inside a plan's included allowance favors subscriptions like ElevenLabs' $49/month Pro tier; bursty or unpredictable volume favors per-unit credit pricing, since you're not paying for quiet months.
Should I always pick the cheapest TTS API? No. Price should break a tie between options that already meet your latency, expressiveness, and empathy needs — not override them. A cheaper voice that's wrong for the script costs more once you count the redo.
The takeaway
Cartesia Sonic 4 is the honest answer to "cheapest AI voice API in 2026," and the per-minute math backs it up clearly: roughly a third to a quarter of ElevenLabs' cost at any real volume. But the numbers above are planning estimates built on a stated assumption, not invoiced totals — run your actual script through both before committing a large batch, and check the pick-by-constraint rule before assuming the cheapest option is also the right one for the job.