# Appen vs JustCall Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. JustCall records 780,285 monthly visits with +11.8% growth and Paid pricing. | Metric | [Appen](https://openaitools.app/tool/appen-com) | [JustCall](https://openaitools.app/tool/justcall) | | :--- | :--- | :--- | | Website URL | https://appen.com | https://justcall.io | | Categories | AI Models, Large Language Models (LLMs), AI Developer Tools | AI Agent, AI Call Center, AI Customer Service, AI Sales Assistant | | Pricing Model | Contact for Pricing | Paid | | Monthly Visits | 665,840 | 780,285 | | MoM Growth Rate | +0.2% | +11.8% | | Primary Market | United States | United States | | Direct Visits | 238,314 | 613,001 | | Review Score | 4.4 | 4.4 | | Saved Count | 2 | 1 | | Supported Platforms | Website | Website | ## Appen Appen is one of the oldest pure-play AI data companies, tracing its roots to 1996 when it began building human-labeled datasets for speech recognition and NLP. Over three decades it supported successive generations of model development — search relevance in the 2000s, machine translation, deep-learning vision annotation, Transformer-era semantics, GPT-3 scale corpora, RLHF for conversational AI, and now agentic and multimodal foundation models. Today Appen positions itself around six specialised capability areas: Frontier Alignment (chain-of-thought reasoning traces, SME RLHF, supervised fine-tuning demonstrations, adversarial red teaming), Agentic AI (golden trajectories, RL environment design, failure-mode taxonomies, SWE-driven evaluation), Multimodal and Speech AI (multilingual ASR and conversational corpora, expressive TTS annotation, VLM training data, video action labelling), Physical AI (LiDAR point-cloud annotation, multi-camera sensor fusion, robotics demonstration trajectories, world-model rollouts), Model Integrity (hallucination benchmarking, bias detection, regulatory audits and continuous monitoring), and Research Services (context engineering, calibrated LLM-as-a-judge, synthetic data and custom benchmarking). Delivery runs through Appen's AI Data Platform (ADAP), which blends automation with human oversight, and the company cites SOC 2 and ISO 27001 certification, 500+ global locales, and a client roster that includes major cloud, search, retail and aerospace organisations. Appen does not publish self-serve pricing; engagements start with a scoping conversation and are quoted per project, so cost depends on data volume, language coverage, modality and annotation complexity. **Pricing & Plans:** Enterprise/contact-for-pricing. Appen does not publish self-serve plans; projects are scoped and quoted individually. Appen also sells off-the-shelf (OTS) datasets and crowd/contractor workforce programs with separate terms. - **Frontier alignment data:** Chain-of-thought reasoning traces, SME-level RLHF, supervised fine-tuning demonstrations and adversarial red teaming for the most capable models. - **Agentic AI datasets:** Golden trajectories, RL environment design, failure-mode taxonomies and software-engineering-driven deep evaluation for autonomous agents. - **Multimodal and speech corpora:** Multilingual ASR and conversational speech data, expressive TTS annotation, vision-language model training data, video action labelling and voice-agent evaluation. - **Physical AI annotation:** LiDAR point-cloud labeling, multi-camera sensor fusion, robot demonstration trajectories, world-model rollouts and embodied interaction logs. - **Model integrity and evaluation:** Hallucination benchmarking, bias detection, regulatory audits and continuous monitoring, plus independent model evaluation. - **AI Data Platform (ADAP):** A production platform that combines automation with human oversight, with SOC 2 and ISO 27001 certification and 500+ locales covered. **Strengths:** Three decades of annotation methodology, tooling and workforce management experience; Very broad coverage: frontier alignment, agentic, speech, multimodal, physical AI and evaluation in one vendor; 500+ locales and multilingual expertise that most in-house teams cannot match; Enterprise-grade security posture (SOC 2, ISO 27001) and publicly listed governance **Limitations:** No transparent self-serve pricing; every engagement requires a sales/scoping cycle; Enterprise-oriented contracts can be heavy for small teams or indie developers; Quality depends on workforce management, so results vary by project and locale; Overlaps with many cheaper specialist annotation vendors, making vendor selection non-trivial [Profile (Markdown)](https://openaitools.app/tool/appen-com.md) ## JustCall JustCall bundles a cloud phone system, multi-channel messaging and AI call automation into a single workspace aimed at revenue and support teams. Core telephony covers local, international and toll-free numbers in more than 70 countries, IVR menus, call routing, call recording and advanced analytics, with dialer options spanning power, dynamic and predictive modes plus parallel dialing and local presence. **Pricing & Plans:** Paid plans billed per user per month with a 14-day free trial (no credit card required); higher tiers add dialer capacity and AI features. Contact sales for exact current pricing. - **AI Voice Agents:** Automated agents that resolve calls, qualify leads and route callers 24/7, with escalation to a human when needed. - **Multi-mode Dialers:** Power, dynamic, predictive and parallel dialing with local presence and smart reattempt rules to boost connect rates. - **Conversation Intelligence:** AI call summaries, transcription, sentiment analysis, agent assist and automatic call scoring for coaching at scale. - **Unified Messaging Inbox:** SMS, MMS, RCS and WhatsApp conversations with bulk sending, bots and a shared team inbox. - **100+ Integrations:** Native connections to HubSpot, Salesforce, Pipedrive, Zoho, Zendesk, Slack, Zapier and many more tools. **Strengths:** Broad all-in-one platform covering calling, messaging and AI agents; Strong conversation intelligence and automatic call scoring for coaching; Deep CRM and helpdesk integrations including HubSpot, Salesforce and Zendesk; Number coverage across 70+ countries with local and toll-free options **Limitations:** Per-user pricing with AI features gated to higher tiers; International calling costs vary by destination and add up quickly; Feature breadth can feel overwhelming for very small teams [Profile (Markdown)](https://openaitools.app/tool/justcall.md) ## Frequently Asked Questions ### How do Appen and JustCall compare in monthly traffic? Appen has 665,840 monthly visits, while JustCall has 780,285. Traffic estimates describe audience size, not product quality. ### How do their growth rates compare? Appen has a month-over-month growth rate of +0.2%; JustCall has +11.8%. ### How does pricing compare? Appen: Contact for Pricing. Enterprise/contact-for-pricing. Appen does not publish self-serve plans; projects are scoped and quoted individually. Appen also sells off-the-shelf (OTS) datasets and crowd/contractor workforce programs with separate terms. JustCall: Paid. Paid plans billed per user per month with a 14-day free trial (no credit card required); higher tiers add dialer capacity and AI features. Contact sales for exact current pricing. ## Alternatives | # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | 1 | [Salesforce Agentforce (formerly Einstein)](https://openaitools.app/tool/salesforce-einstein) | 111,910,743 | +2.2% | Freemium | Powerful enterprise AI agent platform for customer service, but tightly coupled to Salesforce rather than standalone like JustCall. | [.md](https://openaitools.app/tool/salesforce-einstein.md) | | 2 | [Prolific](https://openaitools.app/tool/prolific-com) | 18,697,671 | -1.8% | Paid | Connects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines. | [.md](https://openaitools.app/tool/prolific-com.md) | | 3 | [Dialpad](https://openaitools.app/tool/dialpad) | 2,763,687 | +10.7% | Paid | Provides robust cloud calling and AI contact center features, though with a different pricing and UI structure than JustCall. | [.md](https://openaitools.app/tool/dialpad.md) | | 4 | [Invisible Technologies](https://openaitools.app/tool/invisible-technologies-inc) | 1,364,520 | +64.4% | Contact for Pricing | Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service. | [.md](https://openaitools.app/tool/invisible-technologies-inc.md) | | 5 | [Labelbox](https://openaitools.app/tool/labelbox) | 762,803 | -22.8% | Contact for Pricing | Combines robust data labeling tools with automated workflows, but focuses more on software tooling than managed human workforces. | [.md](https://openaitools.app/tool/labelbox.md) | | 6 | [Scale](https://openaitools.app/tool/scale) | 616,915 | +12.5% | Contact for Pricing | Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing. | [.md](https://openaitools.app/tool/scale.md) | | 7 | [Callbell](https://openaitools.app/tool/callbell) | 487,975 | -24% | Freemium, Free Trial, Paid, Contact for Pricing | Unifies messaging apps into a shared team inbox with AI, but lacks JustCall's advanced VoIP phone calling features. | [.md](https://openaitools.app/tool/callbell.md) | | 8 | [SuperAnnotate](https://openaitools.app/tool/super-annotate) | 386,034 | +37.4% | Free Trial, Contact for Pricing | Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks. | [.md](https://openaitools.app/tool/super-annotate.md) | | 9 | [SleekFlow](https://openaitools.app/tool/sleekflow) | 348,111 | -2% | Paid, Contact for Pricing | Strong omnichannel messaging integration for sales and support, but less focused on traditional telephony and cloud calling than JustCall. | [.md](https://openaitools.app/tool/sleekflow.md) | | 10 | [PolyAI](https://openaitools.app/tool/poly-ai-ai) | 319,894 | +24.3% | Contact for Pricing | Enterprise-grade voice AI for complex customer service workflows, but significantly heavier and more expensive than JustCall. | [.md](https://openaitools.app/tool/poly-ai-ai.md) | --- Source: https://openaitools.app/compare/appen-com-vs-justcall More Markdown: [Categories](https://openaitools.app/categories.md) · [Traffic rankings](https://openaitools.app/rankings.md) · [llms.txt](https://openaitools.app/llms.txt)