Top 10 Natural Language Processing (NLP) Training Data Services

Article by Daniel Smith | May 17, 2019

The increasing ease of access to training data has the potential to completely transform the state of machine learning. As a result, the production, cleaning and annotation of datasets is rapidly becoming big business. With so many companies clamoring to provide you with annotation services, it can be difficult to know which ones are worth investigating – and who will provide the greatest ROI.

Below is a list of the most prominent providers of training data for a variety of NLP projects. As important players in the field, these companies are a great place to start your search for that perfect dataset.


Best NLP Training Data Services

Lionbridge AI: With 500,000 contributors and capabilities in over 300 languages, Lionbridge is one of the leading providers of training data for NLP tasks. They are able to create, clean, and annotate training data for a diverse range of use cases, as well as build out custom workflows to suit any specialist project requirements.

Amazon Mechanical Turk: One of the early players in the field of data annotation, AMT’s crowd is a cheap, scalable solution to your NLP data needs. If you’re prepared to do the legwork of sourcing annotators yourself, they could be a competitive option worth considering.

Appen: With a large range of data annotation capabilities built to serve many different industries, Appen are well-placed to serve a variety of project types. From search relevance to text-to-speech, Appen is a good choice for machine learning data at scale.

Figure Eight: A subsidiary of Appen, Figure Eight is able to label data in a wide array of languages. From named entity recognition to text categorization, their offering is built to serve customers at the enterprise level.

Scale: Although Scale’s business focuses mainly on image and video tagging, they also have some text categorization capabilities. Their categorization and content moderation services are scalable thanks to a combination of human and machine learning annotation practices.

Samasource: Combining social impact with training data services, Samasource specialize in the creation of datasets for document classification, sentiment analysis, and intent recognition. Their workers are able to create both training and validation data for your model.

Alegion: This company offers text and audio annotation services for NLP use cases, including sentiment analysis and text moderation. They train their annotators to meet the specific requirements of each project.

Clickworker: Crowdsourcing website Clickworker offers NLP data annotation as part of their broader data management services. Their crowd is able to build datasets of all sizes, with a particular focus on conversational AI use cases.

Upwork: As one of the largest crowdsourcing players in the market, Upwork have a variety of machine learning capabilities. For unskilled tasks, they are a great source of cheap, scalable labour.

Dataturks: Built with a specific focus on text annotation, Dataturks provide text classification and entity recognition services. They also offer an API that will help you to integrate your labeled dataset with your workflow more easily.


Still can’t find what you need? Lionbridge AI has 20+ years of expertise in building extensive, accurate datasets. With 500,000 linguists working in 300 languages, we’re well placed to build and annotate the custom dataset you’ve been searching for. Contact us now to discover how we can strengthen the foundations of your NLP model.

Improve your NLP model with high-quality data
The Author
Daniel Smith

Daniel writes a variety of content for Lionbridge’s website as part of the marketing team. Born and raised in the UK, he first came to Japan by chance in 2013 and is continually surprised that no one has thrown him out yet. Outside of Lionbridge, he loves to travel, take photos and listen to music that his neighbors really, really hate.


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