Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. LanguageTool records 5,707,795 monthly visits with -4.2% growth and Freemium pricing.
Human-validated training data and evaluation services for frontier AI models
AI grammar, spelling and style checker for 30+ languages
| Dimension / Metric | | |
|---|---|---|
| Official Domain | appen.com | languagetool.org |
| Pricing Model | Contact for Pricing | Freemium |
| Monthly Visits | 665.84K (665,840) | 5.71M (5,707,795) |
| MoM Traffic Delta | +1.1K (+0.2%) | -247.26K (-4.2%) |
| Primary Market & Share | 🇺🇸 United States (22%) | 🇧🇷 Brazil (13.8%) |
| Direct Visits / mo | 238.31K | 3.23M |
| User Rating | 4.4 | 4.3 |
| 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 grammar, spelling and style checker for 30+ languages
Detects grammatical errors, typos, punctuation issues and casing mistakes across 30+ languages.
Rephrase any sentence to be more formal, fluent, simple or concise with AI-driven suggestions.
Browser add-ons plus Google Docs, Word, LibreOffice, Gmail and Outlook integrations, and desktop apps.
Advanced suggestions flag overused phrases, redundancy and wording that weakens your text.
SpecialistEnterprise-grade neural machine translation, AI writing refinement, and real-time voice translation across thirty-plus global languages.
SpecialistEnterprise-grade neural machine translation, AI writing refinement, and real-time voice translation across thirty-plus global languages.
A premier cross-platform writing assistant offering robust real-time grammar checks, tone alignment, and style suggestions.
A premier cross-platform writing assistant offering robust real-time grammar checks, tone alignment, and style suggestions.
SpecialistAn AI writing assistant specializing in advanced paraphrasing and text rewriting alongside built-in grammar checks.
SpecialistAn AI writing assistant specializing in advanced paraphrasing and text rewriting alongside built-in grammar checks.
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.
SpecialistAcademic proofreading, plagiarism checking and AI-powered writing tools in one place
SpecialistAcademic proofreading, plagiarism checking and AI-powered writing tools in one place
A comprehensive writing enhancement platform combining deep style analysis with line-level grammar and spelling correction.
A comprehensive writing enhancement platform combining deep style analysis with line-level grammar and spelling correction.
SpecialistAI translation for text, images, documents and speech in 100+ languages
SpecialistAI translation for text, images, documents and speech in 100+ languages
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.
SpecialistAI academic writing assistant that edits, cites, and checks your manuscript right where you write
SpecialistAI academic writing assistant that edits, cites, and checks your manuscript right where you write
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.
SpecialistA web-based writing tool that highlights readability issues, complex sentences, and style flaws in draft text.
SpecialistA web-based writing tool that highlights readability issues, complex sentences, and style flaws in draft text.
