🏷 Open Source Data Annotation & Labeling Tools

At ZenML we believe that annotation and labeling workflows are a core part of the machine learning lifecycle. As an open-source tool, we wanted to highlight and recognize the variety of tools that are available to help your workflows become more data-centric. We had three core criteria to decide whether a particular tool could make it into the list:

• The tool has an open-source licence.
• The tool is actively maintained.
• The tool is functional and fit for purpose.

We welcome contributions to this list, so if you know of a tool that we've missed or if you've built one yourself, please do create a PR!

🔥 Do you use these tools or do you want to add one to your MLOps stack? At ZenML, we are looking for design partnerships and collaboration to develop the integrations and workflows around using annotation within the MLOps lifecycle. If you'd like to learn more, please join our Slack and leave us a message!

Contents

• Multi Modal / Multi Domain
• Text
• Images
• Audio
• Video
• Time Series
• Other

Multi Modal / Multi Domain

Name	Description	License
Acharya	A Data Centric MLOps tool for your Named Entity Recognition projects	?
Adala	An Autonomous Data (Labeling) Agent framework.	Apache-2
Classifai	A comprehensive open-source data annotation platform	Apache-2
Computer Vision Annotation Tool (CVAT)	A free, online, interactive video and image annotation tool for computer vision	MIT
Data Annotator for Machine Learning (DAML)	An application that helps machine learning teams facilitating the creation and management of annotations	Apache-2
DataGym	Open source annotation and labeling tool for image and video assets	MIT
Diffgram	Training Data (Data Labeling, Annotation, Workflow) for all Data Types (Image, Video, 3D, Text, Geo, Audio, more) at scale	ELv2
Hover	Explore and label on a map of raw data. Handles text, audio and images.	MIT
Label Studio	A multi-type data labeling and annotation tool with standardized output format	Apache-2
Pigeon	A simple widget that lets you quickly annotate a dataset of unlabeled examples from the comfort of your Jupyter notebook	Apache-2
QSL: Quick and Simple Labeler	A quick and simple tool for labeling images, videos and time series data, right from Jupyter	MIT
Shoonya	Platform to Annotate and label data at scale	MIT
Tator	Video analytics web platform	AGPL-3
TornadoAi	A human-in-the-loop machine learning framework	AGPL-3
Universal Data Tool	A web/desktop app for editing and annotating images, text, audio, documents and to view and edit any data defined in the extensible .udt.json and .udt.csv standard	MIT
VGG Image Annotator (VIA)	A standalone image annotator application packaged as a single HTML file (< 400 KB) that runs on most modern web browsers	BSD-2
VIAME	Video and Image Analytics for Multiple Environments	Custom
Xtreme1	An all-in-one data labeling and annotation platform for multimodal data training and supports 3D LiDAR point cloud, image, and LLM	Apache-2

Text

Name	Description	License
Annotation Lab	An NLP annotation tool included in spark-nlp	Apache-2
Argilla	A production-ready Python framework for exploring, annotating, and managing data in NLP projects	Apache-2
bulk	Bulk is a quick developer tool to apply some bulk labels	MIT
CoreNLP	A Java suite of core NLP tools	GPL-3
DataQA	Labeling platform for text using weak supervision	GPL-3
doccano	An open source text annotation tool supporting text classification, sequence labeling and sequence to sequence tasks	MIT
FLAT - FoLiA Linguistic Annotation Tool	A web-based linguistic annotation environment based around the FoLiA format, an XML-based format for linguistic annotation	GPL-3
INCEpTION	A semantic annotation platform offering intelligent annotation assistance and knowledge management	Apache-2
knodle	Knodle (Knowledge-supervised Deep Learning Framework)	Apache-2
Markup	A web-based document annotation tool, powered by GPT-4	Unknown
NER Annotator for Spacy	NER Annotator for SpaCy allows you to create training data for creating a custom NER Model with custom tags.	MIT
NPLM	Noisy Partial Label Model(NPLM)	N/A
Potato	An annotation framework with 20+ templates, editable UI, quality control, data management and an option to add a survey for crowdsourcing	PolyForm Shield
refinery	The data scientist's open-source choice to scale, assess and maintain natural language data.	Apache-2
Slate	A Super-Lightweight Annotation Tool for Experts: Label text in a terminal with just Python	ISC
SMART	A tool for building labeled training datasets for supervised machine learning tasks in NLP	MIT
SpaCy annotator	Spacy NER annotator using ipywidgets	N/A
Small-Text	Active Learning for Text Classification	MIT
Snorkel	Programmatically Build and Manage Training Data	Apache-2
skweak	skweak: Weak supervision for NLP	MIT
TALEN	A way to do annotations for NER	Custom
Theme	Minimalistic CLI labeling tool for text classification	MIT
YEDDA	A lightweight collaborative text span annotation tool	Apache-2
WeaSEL	WeaSEL: Weakly Supervised End-to-end Learning	Apache-2

Images

Name	Description	License
3D Slicer	Visualization, processing, segmentation, registration, and analysis of medical, biomedical, and other 3D images and meshes	BSD
Annotate Lab	Simplifying Image Annotation	MIT
Annotorious	A JavaScript library for image annotation	BSD-3
AnyLabeling	Effortless AI-assisted data labeling with AI support from YOLO, Segment Anything, MobileSAM	GPL-3
autodistill	Images to inference with no labeling (use foundation models to train supervised models)	Apache-2
bbox-visualizer	Make drawing and labeling bounding boxes easy as cake	MIT
Bounding Box Editor	A JavaFX desktop application for creating image-object-annotations with bounding boxes	GPL-3
CATMAID	The Collaborative Annotation Toolkit for Massive Amounts of Image Data	GPL-3
COCO Annotator	A web-based image segmentation tool for object detection, localization, and keypoints	MIT
DeepLabel	A cross-platform desktop image annotation tool for machine learning	MIT
ilastik	Segment, classify, track and count your cells or other experimental data	Custom
ImageTagger	An open source online platform for collaborative image labeling	MIT
imglab	A web based tool to label images for objects that can be used to train dlib or other object detectors	MIT
KNOSSOS	A software tool for the visualization and annotation of 3D image data and was developed for the rapid reconstruction of neural morphology and connectivity	GPL-2
labelCloud	A lightweight tool for labeling 3D bounding boxes in point clouds	GPL-3
LabelFlow	An open platform for image labeling	Custom
labelme	Image Polygonal Annotation with Python (polygon, rectangle, circle, line, point and image-level flag annotation)	Custom
LabelImg	A graphical image annotation tool and label object bounding boxes in images	MIT
LOST	A flexible web-based framework for semi-automatic image annotation	MIT
Make Sense	A free-to-use online tool for labeling photos	GPL-3
MyVision	Computer vision based ML training data generation tool	GPL-3
OHIF Medical Imaging Viewer	OHIF zero-footprint DICOM viewer and oncology specific Lesion Tracker	MIT
OpenLabeler	An open source desktop application for annotating objects for AI appplications	Apache-2
Pixano	A web-based smart-annotation tool for computer vision applications	CeCILL-C
Scalabel	A web-based visual data annotation tool, supporting both 2D and 3D data labeling	Apache-2
webKnossos	A fully cloud- and browser-based 3D annotation tool for distributed large-scale data analysis in light- and electron-microscopy based Connectomics	AGPL-3
Yolo_Label	GUI for marking bounded boxes of objects in images for training neural network YOLO	MIT

Video

Name	Description	License
DIVE	Media annotation and analysis tools for web and desktop	Apache-2
UltimateLabeling	A multi-purpose Video Labeling GUI in Python with integrated SOTA detector and tracker	MIT

Audio

Name	Description	License
aubio	A library for audio and music analysis	GPL-3
audino	Open source audio annotation tool	MIT
Praat	Annotation tool for phonetics analysis	GPL-3
Peaks.js	JavaScript UI component for interacting with audio waveforms	LGPL-3
Wavesurfer.js	Navigable waveform built on Web Audio and Canvas	BSD-3

Time Series

Name	Description	License
sktime	A framework for machine learning with time series	BSD-3

Other

Name	Description	License
Compose	Automated prediction engineering. Allows you to easily structure prediction problems and generate labels for supervised learning	BSD-3
Encord Active	Toolkit to test, validate, and evaluate your models and surface, curate, and prioritize the most valuable data for labeling	Apache-2
NeuroTrALE	Annotation software for brain mapping, supporting 3D imaging and annotation	BSD-2
OpenCRAVAT	A modular annotation tool for genomic variants	MIT
PatchSorter	An open-source digital pathology tool for histologic object labeling	BSD-3
Personal Cancer Genome Reporter (PCGR)	A stand-alone software package for translation of individual tumor genomes for precision cancer medicine	MIT
Quepid	Gather Human Judgements (aka Explicit Ratings) for Search Quality. Also a safe space to play with your search algorithm.	Apache-2

Acknowledgements

Thanks to the creators of these other repositories (and this one!) for getting us going down the path of creating our own. I used these efforts to get started in my survey of the space before adding, updating and pruning as per the open-source and other criteria specified above.