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SoCaptionsvsAssemblyAI

AssemblyAI is an ASR API, not a product. Developers build their own captioning UIs on top. AssemblyAI's accuracy is best-in-class, but you'll spend weeks shipping the editor, styling, and MP4 export that SoCaptions ships out of the box.

Side by side

Feature
AssemblyAI
SoCaptions
Primary audience
Developers building speech AI products
Creators making captioned videos
Output
JSON transcript via API
MP4 with captions, SRT, VTT, ASS, etc.
Editor UI
None — bring your own
Built-in WYSIWYG editor
Caption styling
None
Kinetic, karaoke, box, outline presets
MP4 export
Not included
One-click burned-in MP4
Pricing model
$0.37/hr (Universal-1)
$3/mo flat for 100 min
Time-to-first-caption
Days–weeks of integration
Under a minute
AssemblyAI strengths
  • Best-in-class English WER (~5–6% on clean audio)
  • Powerful API with diarization, sentiment, summarization, content moderation
  • Pay-per-minute pricing scales for high-volume products
AssemblyAI trade-offs
  • No editor — you build the entire UX yourself
  • No video output — you handle MP4 rendering yourself
  • Wrong fit for a single creator captioning their own clips
SoCaptions strengths
  • Editor, styling, and MP4 export shipped
  • Cheaper for caption-only use
  • Zero engineering required
Try SoCaptions free
Choose AssemblyAI if…

You're building a product that needs ASR as a component — meeting bots, voice agents, custom captioning SaaS.

Choose SoCaptions if…

You're a creator who wants captions on your video, not an SDK to integrate.

The verdict

AssemblyAI is the right tool for engineers shipping speech AI products. SoCaptions is the right tool for creators captioning videos. Don't use AssemblyAI to caption your own TikToks.

Frequently asked

How is AssemblyAI's accuracy compared to Whisper?+

AssemblyAI Universal-1 edges Whisper on diarization and slightly on English WER. Whisper edges Universal-1 on accent diversity and language coverage. For most creator workflows the difference is invisible.

Could I rebuild SoCaptions on AssemblyAI?+

Yes — you'd need to build the editor, the timeline, the style presets, the MP4 renderer, and the platform safe-zone overlays. Months of work to match what SoCaptions ships today.

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