OpenAI Realtime API vs Deepgram vs Defapi vs Speechmatics | AI Voice Agents

Which one fits you in 2026? Traffic, pricing, input → output, tasks and community side by side.

Your tool
OpenAI Realtime API
vs
Competitor 1
Deepgram
Competitor 2
DDefapi
Competitor 3
Speechmatics | AI Voice Agents
Compare
4 tools · best value per row highlighted
Your tool OpenAI Realtime API
platform.openai.com
The OpenAI Realtime API is a developer interface for building voice agents that listen and speak in real time.
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Competitor Deepgram
deepgram.com
Deepgram is a voice AI platform that exposes speech-to-text, text-to-speech and conversational agents through APIs.
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Competitor DDefapi
defapi.org
You know how managing multiple AI provider integrations usually means maintaining separate codebases for each vendor
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Competitor Speechmatics | AI Voice Agents
speechmatics.com
Sub-second speech-to-text across 55+ languages with AI voice agents
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Traffic estimated monthly website traffic
Monthly visits
—
—
2.4Kvisits/mo
276.5Kvisits/mo
MoM change
—
—
▼ 42.6%
▼ 8.9%
6-month growth
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-86.2%
+26.7%
Global rank web
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#4,650,820
#155,675
Avg. last 3 months
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4.8K
278.4K
Bounce rate lower is better
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36%
43%
Pages / visit
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—
1.4
3.2
Visit duration
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7s
1m 55s
Traffic sources
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—
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● Direct 87% · ● Referral 12%
OpenAI Realtime APIDeepgramDefapiSpeechmatics | AI Voice Agents
075.9K151.8K227.7K303.5KDefapi · 11.1KDefapi · 13KDefapi · 12.4KDefapi · 17.7KDefapi · 9.4KDefapi · 6.2KDefapi · 7.6KDefapi · 4.2KDefapi · 2.4KSpeechmatics | AI Voice Agents · 170.8KSpeechmatics | AI Voice Agents · 190.6KSpeechmatics | AI Voice Agents · 185.2KSpeechmatics | AI Voice Agents · 218.3KSpeechmatics | AI Voice Agents · 202KSpeechmatics | AI Voice Agents · 206.5KSpeechmatics | AI Voice Agents · 255.1KSpeechmatics | AI Voice Agents · 303.5KSpeechmatics | AI Voice Agents · 276.5K1K10K100K1MDefapi · 11.1KDefapi · 13KDefapi · 12.4KDefapi · 17.7KDefapi · 9.4KDefapi · 6.2KDefapi · 7.6KDefapi · 4.2KDefapi · 2.4KSpeechmatics | AI Voice Agents · 170.8KSpeechmatics | AI Voice Agents · 190.6KSpeechmatics | AI Voice Agents · 185.2KSpeechmatics | AI Voice Agents · 218.3KSpeechmatics | AI Voice Agents · 202KSpeechmatics | AI Voice Agents · 206.5KSpeechmatics | AI Voice Agents · 255.1KSpeechmatics | AI Voice Agents · 303.5KSpeechmatics | AI Voice Agents · 276.5KNov '25DecJan '26FebMarAprMayJunJulAug
Pricing
Model
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Freemium
Paid
Freemium
Starting price
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Free tier
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Free tier
Free tier
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Free trial
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API access
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Plans
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Pay As You Go CustomGrowth $4,000/yrEnterprise Custom
Gemini 3.1 Pro Preview $1/$6/per requestClaude Sonnet 4.6 $1.5/$7.5/per requestClaude Opus 4.6 $2.5/$12.5/per requestSora 2 Stable $0.175+/per request+2 more
Free FreePro $0.13
Capabilities input → output
Input
TextImagesAudio
AudioText
AudioImagesText
Audio
Output
TextAudio
TextAudio
AudioImagesText
Text
Skill level
Advanced
Advanced
Advanced
Advanced
Categories
Development & CodeVoice & SpeechAI APIAI Text-to-Speech+2 more
Development & CodeVoice & SpeechAI APIAI Text-to-Speech+2 more
Development & CodeAI API
Development & CodeVoice & SpeechAI APIAI Transcription
Tasks what each tool can do · 1 shared · core   partial
Tasks covered
9
9
4
3
APIs
Voice agents
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Transcription
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Text to speech
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Developer tools
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Voice assistance
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API integrations
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API management
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Speech recognition
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Voice
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–
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API security
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Agent creation
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–
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Audio translation
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Call transcriptions
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Speech synthesis
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Community on aitoolstime
Rating
no ratings yet
no ratings yet
no ratings yet
no ratings yet
Upvotes
▲ 0
▲ 0
▲ 0
▲ 0
Saves
0
0
0
0
Reviews
0
0
0
0
Prompts
0
0
0
0
Verified listing
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Traffic figures are third-party estimates for the tool's own domain; tools sharing a domain with a bigger product are not counted. Pricing is captured from each tool's site and may lag.