Deepgram vs AssemblyAI Pricing 2026: Speech-to-Text Cost

Deepgram and AssemblyAI are the two speech-to-text APIs a builder compares when adding transcription, captions, or voice features to a 2026 product. Their prices look an order of magnitude apart at a glance, but only because one quotes per minute and the other per hour. This article converts both to the same unit, separates pre-recorded from streaming pricing, and notes the free credits that let you test accuracy before the rate matters.

1. Per-minute vs per-hour: normalize first

The two vendors quote in different units, which is the first thing to fix. Checked on each pricing page on October 18, 2026.

• Deepgram quotes per minute. Nova-3 monolingual pre-recorded is $0.0043/min on pay-as-you-go and $0.0036/min on Growth; multilingual is $0.0052 and $0.0043^[1].
• AssemblyAI quotes per hour. Universal-2 is $0.15/hour; Universal-3.5 Pro, its most accurate async model, is $0.21/hour^[2].

To compare, convert Deepgram's per-minute rate to per hour by multiplying by 60: $0.0043 × 60 = $0.258 per hour. Now the two are in the same unit and the comparison is real. Quoting one vendor per minute and the other per hour is the single most common source of error in speech-to-text cost analysis, because $0.0043 looks far smaller than $0.15 until you realize they measure different amounts of audio.

2. Normalized rates compared

Pre-recorded rates converted to cost per hour of audio, checked October 18, 2026.

Model	Quoted rate	Per hour
Deepgram Nova-3 (pre-recorded, pay-as-you-go)	$0.0043/min[1]	~$0.26/hr
Deepgram Nova-3 (pre-recorded, Growth)	$0.0036/min[1]	~$0.22/hr
AssemblyAI Universal-3.5 Pro (async)	$0.21/hr[2]	$0.21/hr
AssemblyAI Universal-2 (async)	$0.15/hr[2]	$0.15/hr

On the normalized per-hour basis, AssemblyAI's Universal-2 at $0.15/hour is the cheapest pre-recorded option, and Universal-3.5 Pro at $0.21/hour still comes in under Deepgram Nova-3 at about $0.26/hour on pay-as-you-go. On Deepgram's Growth plan the gap to Universal-3.5 Pro narrows to about a cent an hour. These are different models from different vendors, so the comparison is on published rate, not capability.

3. Streaming is priced separately on both

Real-time streaming transcription is priced separately on both platforms:

• Deepgram Nova-3 streaming: $0.0048/min pay-as-you-go, about $0.29/hour, and $0.0042/min on Growth. Deepgram labels these "limited-time promotional rates on streaming"; the regular rates are $0.0077 and $0.0065/min^[1].
• AssemblyAI streaming: Universal-Streaming (English or multilingual) is $0.15/hour, and Universal-3.6 Pro Realtime is $0.45/hour^[2].

For streaming, AssemblyAI's Universal-Streaming at $0.15/hour is cheapest, Deepgram's promotional rate sits in the middle, and AssemblyAI's Pro realtime model is the most expensive. The cheaper vendor depends on the workload (pre-recorded vs streaming), the model tier, and whether Deepgram's promotion still runs when you scale. Decide your use case first, then read the matching rate. To fold transcription spend into your full monthly stack budget, use the AI stack cost calculator.

4. Free credits and trial volume

Both vendors let you test on real audio before paying, which matters because accuracy on your specific audio (accents, domain terms, noise) decides quality more than the rate does:

• Deepgram: $200 free credit on new pay-as-you-go accounts, no credit card required, no expiration^[1]. At $0.0043/min that funds roughly 46,500 minutes of Nova-3 pre-recorded transcription to test with.
• AssemblyAI: a free tier with no credit card required that, per its pricing FAQ, includes up to 185 hours of transcription^[2].

The planning move is to run both free allowances on a representative sample of your actual audio and compare transcription accuracy, not just price. A model that is a fraction of a cent cheaper per minute but produces more errors costs you far more in correction and bad user experience than the rate difference saves.

5. Decision guidance

• Cheapest published pre-recorded rate: AssemblyAI Universal-2 at $0.15/hour.
• Most accurate tier on a budget: AssemblyAI Universal-3.5 Pro at $0.21/hour or Deepgram Nova-3 on Growth at about $0.22/hour; test both on your audio.
• Low-cost streaming: AssemblyAI Universal-Streaming at $0.15/hour; Deepgram Nova-3 streaming at about $0.29/hour while its promotion lasts.
• Before deciding on price: test both free allowances on your real audio. Accuracy on your domain beats a fractional rate difference.
• Always: normalize to the same unit (per hour) before comparing any two quotes.

Re-check each pricing page before committing; speech-to-text rates, model tiers and promotions change often. For the broader AI-vendor cost picture, see the cheapest LLM API ranking and the 2026 AI solopreneur stack. If transcription is one layer inside a full voice agent, the Vapi vs Bland vs Retell voice AI pricing comparison prices the whole call.

All rate figures checked against the official pricing pages on 2026-10-18.

Frequently asked questions

Is Deepgram or AssemblyAI cheaper for transcription in 2026?

For pre-recorded audio, AssemblyAI, by a smaller margin than it used to be. Deepgram bills per minute and AssemblyAI per hour. Deepgram Nova-3 pre-recorded is $0.0043 per minute on pay-as-you-go, about $0.26 per hour, or $0.0036 per minute (about $0.22 per hour) on its Growth plan. AssemblyAI Universal-2 is $0.15 per hour and Universal-3.5 Pro $0.21 per hour. Both vendors' pricing pages were checked on October 18, 2026. Convert both to the same unit before comparing.

Why can't I compare Deepgram and AssemblyAI prices directly?

Because Deepgram publishes per-minute rates and AssemblyAI publishes per-hour rates. Deepgram's $0.0043 per minute looks tiny next to AssemblyAI's $0.15 per hour, but they are not in the same unit. Multiply Deepgram's per-minute rate by 60 to get about $0.26 per hour, then compare. Without that conversion the comparison is meaningless, which is the single most common mistake in speech-to-text cost analysis.

Do Deepgram and AssemblyAI offer free credits?

Yes, both. Deepgram gives new pay-as-you-go accounts a $200 free credit with no credit card required and no expiration. AssemblyAI's free tier needs no credit card either and, per its pricing FAQ, includes up to 185 hours of transcription. Both let you validate transcription quality on real audio before paying, which matters more than the headline rate.

Is Deepgram's streaming price permanent?

No. Deepgram labels its streaming rates as limited-time promotional: Nova-3 streaming is $0.0048 per minute on pay-as-you-go against a regular $0.0077, with no end date given. Budget a streaming workload at the regular rate if it has to hold beyond the promotion.