# Appen vs Custom.MT

Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. Custom.MT records 4,535 monthly visits with -48.8% growth and Contact for Pricing pricing.

| Metric | [Appen](https://openaitools.app/tool/appen-com) | [Custom.MT](https://openaitools.app/tool/custom-mt) |
| :--- | :--- | :--- |
| Website URL | https://appen.com | https://custom.mt |
| Categories | AI Models, Large Language Models (LLMs), AI Developer Tools | AI Translate, AI API, Large Language Models (LLMs), AI Models |
| Pricing Model | Contact for Pricing | Contact for Pricing |
| Monthly Visits | 665,840 | 4,535 |
| MoM Growth Rate | +0.2% | -48.8% |
| Primary Market | United States | United States |
| Direct Visits | 238,314 | 1,775 |
| Review Score | 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)

## Custom.MT

Custom.MT sits at the intersection of machine translation engineering and generative AI localization. The platform gives localization teams a single console for managing translation engines, whether those are off-the-shelf providers or models trained specifically on a client's terminology and style. Because the console connects to the CAT and TMS tools translators already use, MT becomes part of the existing workflow instead of a separate step.

Beyond the software, Custom.MT operates as a language AI partner. Teams can commission evaluation projects to benchmark engines by language, domain and linguist, run an annual translation memory cleanup, or deploy machine translation on their own hardware when confidential content must not leave the building. Automatic post-editing, language data anonymization and in-domain dataset acquisition round out the service catalog.

The audience is localization managers, language service providers and product teams that treat translation quality as a measurable engineering problem. Companies typically begin with a free trial of the console or a discovery call, then scale into fine-tuned or private models as volumes and quality requirements grow.

**Pricing & Plans:** Custom.MT offers a free trial of the AI translation console and a documented API; full pricing for platform access and services is quote-based, with a discovery call recommended for enterprise MT, fine-tuning and on-premise projects.

- **Central engine management:** Manage stock engines and your own custom models from one console, then push them into the linguistic tools your team already works in.
- **MT and LLM engine evaluation:** Compare DeepL, Google, GPT-class and custom models with BLEU, WER and COMET scores plus sample segments to find the best engine per language pair.
- **Model fine-tuning:** Fine-tune translation models on your terminology, style guides and past translations to cut edit distance and post-editing cost.
- **CAT and TMS connectors:** Plugins and extensions for Trados, Smartling, memoQ, XTM Cloud, Smartcat and Shopware keep MT inside existing localization workflows.
- **TMX cleaning and data services:** Clean up stale translation memories, remove personal data and source in-domain training sets for medical, legal, patent and eCommerce content.

**Strengths:** Unusually broad service catalog, from MT evaluation and fine-tuning to on-premise deployment and TMX cleaning; Engine comparison with standard metrics makes quality decisions defensible rather than anecdotal; Plugins for the major CAT and TMS tools mean minimal disruption to existing localization pipelines; Combines software with human expertise, useful for teams without in-house MT engineers

**Limitations:** Enterprise-grade services and on-premise deployments require a discovery call rather than instant self-serve setup; The strongest value (fine-tuning, evaluation, data acquisition) requires localization engineering knowledge to exploit fully; Pricing is not fully transparent on the marketing site for larger service engagements

[Profile (Markdown)](https://openaitools.app/tool/custom-mt.md)

## Frequently Asked Questions

### How do Appen and Custom.MT compare in monthly traffic?

Appen has 665,840 monthly visits, while Custom.MT has 4,535. 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%; Custom.MT has -48.8%.

### 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. Custom.MT: Contact for Pricing. Custom.MT offers a free trial of the AI translation console and a documented API; full pricing for platform access and services is quote-based, with a discovery call recommended for enterprise MT, fine-tuning and on-premise projects.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [DeepL](https://openaitools.app/tool/deepl) | 95,110,871 | -1.7% | Freemium | Enterprise-grade neural machine translation, AI writing refinement, and real-time voice translation across thirty-plus global languages. | [.md](https://openaitools.app/tool/deepl.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 | [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 | [Lara Translate](https://openaitools.app/tool/lara-translate) | 982,359 | -16.1% | Freemium, Paid, Contact for Pricing | Professional AI translation for text, documents, images and audio | [.md](https://openaitools.app/tool/lara-translate.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 | [Lingvanex](https://openaitools.app/tool/lingvanex) | 661,553 | -9% | Contact for Pricing | On-premise translation and speech recognition for enterprises | [.md](https://openaitools.app/tool/lingvanex.md) |
| 7 | [Phrase](https://openaitools.app/tool/phrase) | 639,121 | -8.7% | Free Trial, Paid, Contact for Pricing | AI-powered localization and translation platform for global content | [.md](https://openaitools.app/tool/phrase.md) |
| 8 | [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) |
| 9 | [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) |
| 10 | [MachineTranslation.com](https://openaitools.app/tool/machinetranslation) | 366,899 | +0.5% | Freemium | Free AI translator that cross-checks 22 models for one trusted translation | [.md](https://openaitools.app/tool/machinetranslation.md) |

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

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