Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. CapSolver records 73,385 monthly visits with -30.9% growth and Free Trial, Paid pricing.
Human-validated training data and evaluation services for frontier AI models
AI CAPTCHA recognition API for reCAPTCHA, Cloudflare and more
| Dimension / Metric | | |
|---|---|---|
| Official Domain | appen.com | dashboard.capsolver.com |
| Pricing Model | Contact for Pricing | Free Trial, Paid |
| Monthly Visits | 665.84K (665,840) | 73.39K (73,385) |
| MoM Traffic Delta | +1.1K (+0.2%) | -32.82K (-30.9%) |
| Primary Market & Share | 🇺🇸 United States (22%) | 🇺🇸 United States (29.6%) |
| Direct Visits / mo | 238.31K | 55.2K |
| User Rating | 4.4 | 4.2 |
| 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.
AI CAPTCHA recognition API for reCAPTCHA, Cloudflare and more
Handles popular challenge types including reCAPTCHA, hCaptcha, Cloudflare Turnstile, and image or OCR-based recognition.
A straightforward HTTP API lets developers submit challenges and receive solution tokens programmatically.
Extensions and browser-automation hooks make it easier to solve challenges inside real browsing sessions.
Image recognition plus OCR models are applied to text and picture CAPTCHAs as well as interactive puzzles.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.
Free / Open-sourceBuild, train, and deploy computer vision for the physical world
Free / Open-sourceBuild, train, and deploy computer vision for the physical world
Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.
Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.
AI-powered CAPTCHA solving API built for scale
AI-powered CAPTCHA solving API built for scale
Combines robust data labeling tools with automated workflows, but focuses more on software tooling than managed human workforces.
Combines robust data labeling tools with automated workflows, but focuses more on software tooling than managed human workforces.
Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing.
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.
Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks.
Multi-modal AI detection API that flags synthetic images, text, audio, video and deepfakes
Multi-modal AI detection API that flags synthetic images, text, audio, video and deepfakes
Search foundation built from embeddings, rerankers, and reader APIs
SpecialistAgent observability, evaluation, and continuous improvement for production AI
SpecialistAgent observability, evaluation, and continuous improvement for production AI
SpecialistThe multimodal data layer for computer vision and physical AI teams
SpecialistThe multimodal data layer for computer vision and physical AI teams
Cloud browsers for AI agents, scraping, and automation that won't get blocked
Cloud browsers for AI agents, scraping, and automation that won't get blocked
