Practical overview
When it fits
Use Flair when an NLP workflow needs Python interfaces for pretrained text models, embeddings or model experimentation within a PyTorch-based framework.
Who it is for
- Python developers adding NLP predictions to applications or analysis workflows.
- Researchers and practitioners experimenting with NLP models and embeddings.
- Teams working with text tasks such as entity recognition, tagging, sentiment analysis or biomedical text.
Documented uses
- Identify named entities in sentences.
- Classify text for sentiment or other supported categories.
- Apply part-of-speech tagging, sense disambiguation and sequence-labeling models.
- Use or combine word and document embeddings.
- Train models and experiment with NLP approaches using PyTorch.
Requirements & limits
The project is open source; its repository displays an MIT license badge. Installation is documented with pip, and Python 3.9 or later is required.
- Flair is a library and framework for developers, rather than a hosted text-analysis service.
- It builds directly on PyTorch and supports applying models as well as training and experimentation.
- The documented NLP scope includes named-entity recognition, sentiment analysis, part-of-speech tagging, classification, embeddings and biomedical text.
- The repository README describes support for a growing number of languages and lists example NER models for English, German, Dutch and Spanish.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Install Flair and tag named entities
Install the framework and use its documented example to predict entity tags for a sentence.
Before you start
- Python 3.9 or later
- A Python virtual environment
- pip
Steps
Install Flair with the command below.
pip install flairImport
Sentencefromflair.dataandClassifierfromflair.nn.Create a
Sentence, load a classifier withClassifier.load('ner'), and callpredict(sentence).Print the sentence to inspect its annotations.
Expected outcome
The README example tags “Berlin” as a location entity in “I love Berlin .”
Guide limitations
- This recipe covers the README's example prediction flow, not model training or deployment.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 12 October 2026
- Original website title
- flairNLP/flair · Official homepage title · retained in its source language

