SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.

Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. Brilliant records 2,426,610 monthly visits with -11.9% growth and Freemium pricing.

Human-validated training data and evaluation services for frontier AI models
| Dimension / Metric | ![]() | ![]() |
|---|---|---|
| Official Domain | appen.com | brilliant.org |
| Pricing Model | Contact for Pricing | Freemium |
| Monthly Visits | 665.84K (665,840) | 2.43M (2,426,610) |
| MoM Traffic Delta |
| +1.1K (+0.2%) |
| -326.35K (-11.9%) |
| Primary Market & Share | 🇺🇸 United States (22%) | 🇺🇸 United States (41.9%) |
|---|
| Direct Visits / mo | 238.31K | 1.2M |
|---|
| User Rating | 4.4 | 4.6 |
|---|
| Supported Platforms | Website | Website |
|---|

Human-validated training data and evaluation services for frontier AI models
Chain-of-thought reasoning traces, SME-level RLHF, supervised fine-tuning demonstrations and adversarial red teaming for the most capable models.
Golden trajectories, RL environment design, failure-mode taxonomies and software-engineering-driven deep evaluation for autonomous agents.
Multilingual ASR and conversational speech data, expressive TTS annotation, vision-language model training data, video action labelling and voice-agent evaluation.
LiDAR point-cloud labeling, multi-camera sensor fusion, robot demonstration trajectories, world-model rollouts and embodied interaction logs.

Interactive math, coding and AI tutoring you learn by doing
Learn math, science, CS and AI through short, visual exercises that build intuition step by step rather than passive video watching.
A visual, interactive tutor that works on a shared canvas, asks guiding questions and gives hints without simply revealing the answer.
Quizzes and reviews adapt to your level, tracking what you have mastered and resurfacing topics that still need work.
Write and run real code to learn programming logic, algorithms, data structures and debugging skills relevant to the AI era.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.

SpecialistFocuses specifically on interactive programming and coding lessons, whereas Brilliant covers broad STEM and math concepts.

SpecialistYour personal AI tutor for every subject, from notes to exam day.

SpecialistProvides deep interactive training for data science and programming, but omits foundational math and general science topics.


Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.


SpecialistAI-powered A Level and GCSE courses with a top-grades-or-refund guarantee
SpecialistLearn Linux, DevOps, and cybersecurity by doing — inside real online labs.

Combines robust data labeling tools with automated workflows, but focuses more on software tooling than managed human workforces.

Excels at step-by-step homework solving and AI tutoring, but provides less structured visual concept-building courses.
Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing.

Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks.

SpecialistProvides adaptive daily math and logic practice for children, but has less emphasis on advanced visual science lessons.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.
Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.
SpecialistLearn Linux, DevOps, and cybersecurity by doing — inside real online labs.
Combines robust data labeling tools with automated workflows, but focuses more on software tooling than managed human workforces.
Excels at step-by-step homework solving and AI tutoring, but provides less structured visual concept-building courses.
Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing.
Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks.