kitio.aiAppen vs Defined.ai
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Appen starts at See pricing page and Defined.ai starts at See pricing page. Check both pricing pages for current plans.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Custom data collection
- RLHF and red teaming
- Speech and multimodal annotation
- LiDAR and robotics labeling
- Off-the-shelf datasets
- AI Data Platform (ADAP)
- Dataset marketplace
- Text, audio, image and video annotation
- Custom data collection
- Model and data evaluation
- Multilingual speech data
- Developer API
| Feature | Appen | Defined.ai |
|---|---|---|
| Best for | Human-annotated training data and model evaluation for AI teams | Training data marketplace and annotation services for enterprise AI |
| Category | Data & analytics | Data & analytics |
| Pricing model | Paid | Paid |
| Starting price | See pricing page | See pricing page |
| Free plan | No | No |
| Made by | Appen | Defined.ai |
| Based in | Australia | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Both offer: Custom data collection.
Pricing compared
Appen starts at See pricing page and Defined.ai starts at See pricing page. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
Prices in USD, checked Oct 29, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Appen
- Covers text, speech, vision and code data
- Coverage in over 500 locales
- SOC 2 and ISO 27001 certified
- Project-based pricing via sales
- Service-heavy rather than self-serve
- Mainly for larger AI teams
Defined.ai
- Covers many languages and data types
- Off-the-shelf datasets plus custom projects
- Human review on labeled data
- No public pricing
- Custom projects go through sales
- Aimed at enterprises rather than individuals
Which one should you choose?
Choose Appen if you want:
- Covers text, speech, vision and code data
- Coverage in over 500 locales
- SOC 2 and ISO 27001 certified
Watch out: project-based pricing via sales.
Choose Defined.ai if you want:
- Covers many languages and data types
- Off-the-shelf datasets plus custom projects
- Human review on labeled data
Watch out: no public pricing.
Appen vs Defined.ai FAQ
What is the difference between Appen and Defined.ai?
Appen: Human-annotated training data and model evaluation for AI teams. Defined.ai: Training data marketplace and annotation services for enterprise AI. Both are data & analytics tools.
Is Appen or Defined.ai cheaper?
Appen starts at See pricing page and Defined.ai starts at See pricing page. Check both pricing pages for current plans.
Do Appen and Defined.ai have free plans?
Appen: No. Defined.ai: No.
Who makes Appen?
Appen is made by Appen, based in Australia.
Who makes Defined.ai?
Defined.ai is made by Defined.ai, based in United States.
Which should I choose, Appen or Defined.ai?
Choose Appen if you value covers text, speech, vision and code data and coverage in over 500 locales. Choose Defined.ai if you value covers many languages and data types and off-the-shelf datasets plus custom projects.