# Appen vs Underpin

Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. Underpin records 0 monthly visits with — growth and Freemium pricing.

| Metric | [Appen](https://openaitools.app/tool/appen-com) | [Underpin](https://openaitools.app/tool/underpin) |
| :--- | :--- | :--- |
| Website URL | https://appen.com | https://chromewebstore.google.com/detail/underpin/kdbncjnjdflmhnoknhdgbnlmjkmeifmg |
| Categories | AI Models, Large Language Models (LLMs), AI Developer Tools | AI Recruiting, AI Checker, AI Task Management, AI Productivity Tools |
| Pricing Model | Contact for Pricing | Freemium |
| Monthly Visits | 665,840 | 0 |
| MoM Growth Rate | +0.2% | — |
| Primary Market | United States | Global |
| Direct Visits | 238,314 | 0 |
| Review Score | 4.4 | 4.2 |
| Saved Count | 2 | 0 |
| Supported Platforms | Website | Browser Extension |

## 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)

## Underpin

Underpin is a lightweight Chrome extension built for people who apply to many jobs and lose track of where they have already applied. Rather than making you log every submission by hand, it watches the pages you use to apply and records each application as it happens, building a personal history of your job search without extra spreadsheets.

The extension's headline feature is duplicate detection. Because it remembers your previous applications, Underpin can warn you when a current listing matches a role or company you have already applied to, so you avoid wasting effort and avoid looking repetitive to recruiters. It also helps you focus on genuinely new openings instead of re-treading familiar ones.

Underpin runs in the background as a popup-driven extension and keeps your data private, with the developer declaring no collection or sale of user data. It is distributed through the Chrome Web Store as a free-to-install tool, making it an easy addition to an existing job-search workflow.

**Pricing & Plans:** Free to install from the Chrome Web Store, with the developer offering it on a freemium basis for extended use.

- **Automatic application tracking:** Detects job application pages as you use them and records each submission automatically, so you do not have to log anything manually.
- **Duplicate application alerts:** Compares new listings against your history and warns you when you are about to apply to a role you have already submitted to.
- **Focus on new openings:** Keeps a running record of where you have applied so you can concentrate your time on fresh opportunities rather than repeats.
- **Popup workflow:** Access your tracked applications through a simple extension popup that opens alongside the site you are already browsing.
- **Privacy-minded design:** The developer states that data is not collected, sold, or shared for unrelated purposes.

**Strengths:** Removes the manual burden of logging job applications; Duplicate-detection warnings directly save time and effort; Free to install as a Chrome extension; Developer declares no data collection or selling

**Limitations:** Only available as a Chrome browser extension; Provides tracking and alerts rather than end-to-end application automation

[Profile (Markdown)](https://openaitools.app/tool/underpin.md)

## Frequently Asked Questions

### How do Appen and Underpin compare in monthly traffic?

Appen has 665,840 monthly visits, while Underpin has 0. 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%; Underpin has —.

### 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. Underpin: Freemium. Free to install from the Chrome Web Store, with the developer offering it on a freemium basis for extended use.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [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) |
| 2 | [Workable](https://openaitools.app/tool/workable) | 10,780,627 | +5.5% | Free Trial, Paid | The agent recruits, you manage talent | [.md](https://openaitools.app/tool/workable.md) |
| 3 | [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) |
| 4 | [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) |
| 5 | [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) |
| 6 | [Kula AI](https://openaitools.app/tool/kula-ai) | 492,326 | +4.2% | Paid, Contact for Pricing | The AI-native ATS that replaces your entire recruiting stack | [.md](https://openaitools.app/tool/kula-ai.md) |
| 7 | [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) |
| 8 | [Arize AI](https://openaitools.app/tool/arize-com) | 249,028 | +3.2% | Paid, Contact for Pricing | Agent observability, evaluation, and continuous improvement for production AI | [.md](https://openaitools.app/tool/arize-com.md) |
| 9 | [Encord](https://openaitools.app/tool/encord-com) | 244,204 | +9.4% | Contact for Pricing | The multimodal data layer for computer vision and physical AI teams | [.md](https://openaitools.app/tool/encord-com.md) |
| 10 | [Alex AI](https://openaitools.app/tool/alex-ai) | 235,876 | +49.3% | Contact for Pricing | An AI recruiter that interviews, verifies, and screens every applicant | [.md](https://openaitools.app/tool/alex-ai.md) |

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Source: https://openaitools.app/compare/appen-com-vs-underpin

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