The AI Annotation Platform

Create high quality training data and integrate your annotation process seamless into your machine learning pipelines.

Our annotation and API products

We support different types of annotations, optimized for your use cases.

Natural Language Annotation

Text Classification Annotation

Create training data for text classification use cases with one or multiple labels per text.

Entity Annotation

Annotate multiple entities within a text and export in various ready to use formats.

Sequence to Sequence Annotation

Optimized for sequence to sequence models or similar uses cases. Upload a text and add multiple variants for it.

Sentiment Annotation

Annotate text to determines whether a text is positive, negative or neutral.


Relationship Annotation

Create relationship mappings between entities in text.

Computer Vision Annotation

Image Classification Annotation

Create annotated datasets for image classification uses cases.


Image Similarity Search

We enable you to integrate image similarity search capabilities into your products and applications.


IO Annotator will speedup your image and text annotation significant. Reduce cost and increase output.



We provide features for everyone in your team. Fast annotation interfaces for your annotators. Metrics to analyze your dataset and an API to integrate it into your pipelines.


Use the annotation tool which fits the best to your use case.


Use our API to integrate your annotations directly into your machine learning pipelines.

Work together

We support multi-user annotations, annotate simultaneously on a dataset.


Keep track of your annotation progress and get useful insights.


Easily add and manage your annotation team.


There is no need to use a mouse, speed up your annotations with shortcuts.


Review your annotations to increase the quality of your datasets.


Webhooks are a way for your machine learning backend to receive realtime updates.

Python SDK soon

Integrate our platform directly into your Jupyter Notebooks or data pipeline.


Dictionaries can be used to speed up your annotation process by pre annotating entities.


How it works


Upload your data to our platform via API or Interface.


We support different types of annotations and provide you an interface to annotate your data at scale.


Integrate your data in your ML pipelines by using our export API, Webhooks or Export user interface.

Thank you

Our customers and partners

partner twt

"We look forward to the partnership with IO Annotator. This way we can offer our customers a tool that simplifies and speeds up the annotation of images and text."


Pascal Reddig
CEO TWT Business Solutions

partner twt

We provide our annotation software to Ph.D. candidates who are using it as part of their Ph.D. thesis. The University of Idaho, based in the Northwest, is a leading research school.

partner twt

Arolsen Archives is an internationally governed centre for documentation, information and research on Nazi persecution, forced labour and the Holocaust in Nazi Germany and its occupied regions.

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