The text annotation tool to train AI

Turn text into intelligence. Easy.


PDF logo; PDF Web-Based EditorDiscover our new PDF annotation tool!

Web-Based Annotation Tool - tagtog


Get relevant insights from text, automatically

Discover patterns, identify challenges, realize solutions


  • > Analyze user feedback and design specific actions for improvement
  • > Enrich your unstructured text with metadata and make it searchable
  • > Find out bid opportunities in your industry
NLP Text Annotation Tool

Train your own AI

Generate training data for your own ML methods

tagtog is as its core a NLP text annotation tool. Create labeled corpora in 3 ways:

  • > Have your team to annotate text manually. Import pre-annotated data too.
  • > Let tagtog's team of human annotators label the data for you
  • > Use machine-learning models to work at scale and semi-supervised

See some of the public corpora created by other users


  1. Import text

    Upload your own files (PDFs, plain text, source code files, ...) or point to external resources like web URLs

  2. Customize

    Choose already trained machines to annotate text automatically (e.g. vehicle parts or genetic diseases) or customize tagtog to your unique context. Use our text annotation tool to give feedback on the predictions and thus, improve the accuracy of the AI to improve your results.

  3. Results

    Numbers are good. Visualizations are better. Understand the results at a glance and export them in various formats. Use our search engine to discover actionable insights and make smarter decisions. That’s it!


  • Machine Learning Tool - Artificial Brain / Artificial Neural Network

    Machine Learning with people on the loop

    Provide feedback by your team of subject-matter experts. Improve the accuracy of your machines and adapt them to find what you need precisely. More information.

  • Democratize Text Analytics

    No Coding or Data Engineering skills required

    Democratize Text Analytics. You don’t need to code or juggle with data to use tagtog. Use the intuitive web interface to create high-quality training data by just annotating.

  • AI Web Editor Tool

    Text Annotation Tool

    The best text annotation tool. Intuitively enrich text: categorize documents, annotate and disambiguate entities (e.g. company products, intents, etc. ), or draw relations (e.g. diseases caused by mutations). More information.

    Do you want to train your own algorithms? Import your predictions, correct them in the annotation tool, and feed them back.

  • PDF Annotation Tool

    Multiple formats

    Work directly with your documents, not only plain text. Annotate natively over PDF or import the text from TXT files, HTML, PDF files, source code files, Markdown, etc.

  • Adaptive Intelligent Machines: As simple as a Git fork

    Marketplace for Intelligent Machines

    Use already-trained machines to analyze your text or boost the creation of training data. Want to identify genetic mutations? vehicle parts? tweets supporting a specific political trend? We've got you.

    Is your machine not there yet? Don't wait, create it and train it yourself. You can also offer your newly-created awesome machine to other users.

  • Concept Search Tool; Finding Retrieval

    Concept Search

    Search in text collections not by keyword, but by concept (e.g. find all vehicle technical reports that are related to engine failures). More information.

Quick Training Services

Quick training

Use already-trained machines, no new training required. Additionally, upload already-annotated documents or term dictionaries to reduce dramatically the time required for subsequent trainings.

Cloud and On-Premises symbol

On our secure Cloud or On-premises

On the Cloud, there is nothing to install, no servers to worry about: start right now. On-premises, run tagtog as a docker image in your own infrastructure. In both cases, just use your favorite browser. More information.

API Services


Integrate tagtog within your existing pipeline. Use the API to upload text and retrieve the results. You can also use it to search across your text collection or improve your search engine. More information.

Team Collaboration

Team Collaboration

Invite other users to help you annotate text and create an annotated corpus. Split tasks, create guidelines, and review annotations together. More information.

Entity Normalization

Entity Normalization

Manage disambiguation. tagtog determines the identity of the annotations assigning unique ids from standard databases such as UniProt or Wikipedia.

You can also upload your own dictionaries to map the annotations to your unique internal references (e.g. product ref). More information.

Big Text Annotation

Big Text

Work with external text sources (e.g. PubMed) or your own files. Process millions of documents with ease.

PDF icon


PDF annotation example
  • Colorful annotations

    Annotate over the PDF

    Annotate directly over the native PDF layout, annotators love it! 💖

  • Loop symbol

    Train your models easily

    Import/Export annotations using text offsets or coordinates, tagtog gives you also the text contained in the PDF to facilitate the processing and generation of annotations.

  • Colorful graph bars

    Annotate any text in the PDF

    Annotate text in figures, tables, pictures, etc.


Save Time & Costs

Save time & costs

Tap Opportunities

Tap opportunities faster than the competition

Removing Repetitive Work for the Group Organization (Team)

Enable your team by removing repetitive work



Download our PDF icon official Product brief