6 best named entity recognition APIs for entity detection
In this article, we’ll look at what exactly named entity recognition is, how it works, the best APIs for performing entity detection, and some of its top use cases.
Named Entity Recognition (NER) APIs have become essential tools for developers building applications that need to extract meaningful information from text. These APIs automatically identify and categorize key information—like names, organizations, locations, and other entities—transforming unstructured text into structured, actionable data.
Whether you're analyzing customer feedback, building conversation intelligence platforms, or processing transcripts from audio streams, NER APIs provide the foundation for understanding what matters most in your text data. The challenge isn't finding an NER solution—it's choosing the right one from the growing ecosystem of providers, each with different strengths in accuracy, features, and implementation approaches.
In this article, we'll explore what Named Entity Recognition is, how these APIs work under the hood, and evaluate the best NER APIs available today. We'll also cover practical implementation guidance to help you integrate entity detection into your applications.
What is Named Entity Recognition, or entity detection?
Named Entity Recognition (NER) is an AI-powered process that automatically identifies and categorizes specific information—like names, locations, organizations, and dates—within text documents, social media posts, or audio transcriptions.
Product teams and developers use entity detection to locate the names of people, organizations, or other "entities" such as addresses, phone numbers, social security numbers, locations, and more. The technology has evolved from simple pattern matching to sophisticated AI models that understand context and meaning.
Entity detection is fundamentally a two-step process:
Identifying entities – detecting that "Apple" or "John Smith" are important elements in the text
Classifying the entities – determining whether "Apple" refers to the company (ORGANIZATION) or the fruit (PRODUCT), or that "John Smith" is a PERSON
For example, in the sentence "Tim Cook announced that Apple will open a new store in New York City next month," an NER API would identify:
"Tim Cook" -> `person_name`
"Apple" -> `organization`
"New York City" -> `location`
"next month" -> `date`
This structured extraction enables applications to automatically understand who's involved, what organizations are mentioned, where events occur, and when they happen—all without manual processing.
How does entity detection work?
Named Entity Recognition works by analyzing text to identify notable objects and their relationships. This process proves particularly valuable when extracting entities from transcripts generated by speech-to-text APIs, where understanding spoken content at scale becomes critical for businesses.
As mentioned above, NER must both identify and categorize information. Modern systems use two main approaches to achieve this goal:
Ontology-based approaches
Ontology-based Named Entity Recognition uses knowledge-based recognition that relies on predefined lists and rules. For instance, it might have a database of company names, a list of common first and last names, or geographic locations. When processing text, the system matches words against these lists to identify entities.
While this approach can work well for domains with well-defined terminology—like medical fields with standardized drug names or legal documents with specific terminology—its accuracy depends heavily on how comprehensive and current the underlying databases are. It struggles with new entities, misspellings, or entities mentioned in unexpected contexts.
Test Entity Detection in Minutes
Try AssemblyAI’s Playground to run entity detection on sample audio or your files. See people, organizations, locations, and more extracted instantly.
AI model-based Named Entity Recognition uses trained neural networks to understand the semantic and syntactic relationships between words and phrases. These models learn from massive, diverse datasets, allowing them to identify entities based on context rather than just matching against lists.
For example, an AI model can recognize "Tesla" as a company when it appears near words like "earnings" or "CEO," but might classify it as a person when discussing historical scientists. This contextual understanding makes AI-based approaches significantly more accurate and flexible than ontology-based systems, especially when dealing with:
Previously unseen entities
Ambiguous references
Entities in multiple languages
Informal or conversational text
Most modern NER APIs use AI model-based approaches, often enhanced with transformer architectures that power today's most advanced language understanding systems.
Common entity types
Different NER APIs support varying sets of entities. While most handle common categories like PERSON, ORGANIZATION, and LOCATION, specialized providers offer domain-specific entities such as medical conditions, financial instruments, or technical terminology. When evaluating APIs, consider which entity types are critical for your use case.
For example, AssemblyAI supports a wide range of entities, from common types like names and locations to sensitive PII like credit card and social security numbers. For the complete, up-to-date list, please see the Supported Entities table in our documentation.
Top use cases for NER APIs
Why is entity detection important? Entity detection can be an extremely valuable data collection and analytical tool for product teams and developers across a wide range of industries.
Modern applications leverage NER APIs across diverse industries:
Telephony and CRM platforms
Companies like CallSource and Ringostat use NER to identify specific people, company, or competitor names from call transcripts and automatically populate CRM fields. This automation improves response times by instantly categorizing conversations and surfacing critical information to sales and support teams.
Hiring and recruitment platforms
Recruitment platforms extract roles, companies, skills, and salary information from resumes and job postings. This enables recruiters to quickly match candidates with opportunities and build searchable talent databases without manual data entry.
Virtual meeting and collaboration tools
Platforms like Recall and Dyte leverage NER to identify participants, companies, and discussion topics from meeting transcripts. This data powers features like automatic meeting summaries, action item extraction, and knowledge management systems.
Voice assistants and conversational AI
Voice bots use entity detection to identify people, companies, or products mentioned in conversations. This enables them to trigger contextually appropriate actions and personalize responses based on extracted information.
Healthcare and medical documentation
In HIPAA-compliant environments, NER identifies medical conditions, medications, procedures, and patient information from clinical notes and transcribed consultations. Companies like T-Pro use this technology to automate medical documentation while maintaining regulatory compliance.
Enterprise-Grade Entity Detection
Working with regulated data or healthcare use cases? Talk with our team about security, compliance, and deployment options tailored to your requirements.
News organizations and brand monitoring services use NER to track mentions of companies, products, and public figures across thousands of articles, broadcasts, and social media posts. This enables real-time reputation management and competitive intelligence.
By collecting entity information systematically, product teams gain invaluable insights into customer behavior, market trends, and operational patterns. These insights drive better decision-making across marketing campaigns, product development, and strategic planning.
How to evaluate NER APIs
When choosing a Named Entity Recognition API, success depends on finding a solution that matches your specific technical requirements, use case, and scale.
Key evaluation criteria include:
Accuracy and performance benchmarks
Look for providers that publish accuracy metrics and offer free tiers for testing. Evaluate performance on your specific data type—medical transcripts require different capabilities than social media posts.
Entity coverage and customization
Review the supported entity types against your requirements. Basic APIs might only detect people, places, and organizations, while advanced solutions include dates, monetary values, and industry-specific entities.
Processing speed and scalability
For real-time applications like voice assistants, latency matters most. Batch processing applications prioritize throughput over speed.
Developer experience and integration
Strong documentation, client libraries, and clear code examples accelerate implementation. Look for APIs with straightforward authentication and consistent response formats.
Data security and compliance
For sensitive applications, verify security certifications (SOC 2, ISO 27001), data handling practices, and compliance with regulations like GDPR or HIPAA.
Pricing model and total cost
Compare pricing structures carefully. Some providers charge per request, others by character count or processing time.
What are the best entity detection APIs for Named Entity Recognition?
Now that we've covered evaluation criteria, lets examine the leading entity detection APIs available today. Note that some APIs specialize in processing existing text, while others perform entity detection on audio or video streams while simultaneously transcribing them.
1. AssemblyAI
AssemblyAI's Entity Detection, part of its suite of Speech Understanding models, detects a wide range of entities from transcribed audio at industry-leading accuracy. The API excels at processing conversational speech, making it ideal for call centers, meeting platforms, and voice applications. AssemblyAI's entity detection capabilities include PII like `driver’s_license` and `banking_information`(including account and routing numbers).
Developers and product managers use AssemblyAI's Entity Detection API across diverse AI applications, including Revenue Intelligence Platforms and Conversation Intelligence Platforms. The API integrates seamlessly with AssemblyAI's speech-to-text capabilities, allowing you to transcribe and analyze audio in a single API call.
2. Dandelion
Dandelion offers entity extraction for documents and social media content. The European-based API supports multiple languages including English, Italian, French, German, Portuguese, Spanish, and Russian with varying accuracy levels. While specific entity types aren't publicly documented, the service focuses on web content and social media analysis.
Developers can test the Entity Detection tool free up to a certain threshold, making it accessible for prototyping and small projects.
3. Google Natural Language
Google's Natural Language API provides entity analysis and extraction alongside sentiment analysis, syntax analysis, and content classification. Their service offers two components:
Entity Analysis - identifies entities in documents like contracts and receipts, labeling them by type using Google's pre-trained models
Custom Entity Extraction - allows training custom models to identify domain-specific entities using your own labeled data
While Google's Natural Language API has higher pricing than some alternatives, it offers a free tier for up to 5,000 units monthly. Developers can combine it with Google's Cloud Speech-to-Text for audio processing, though this requires managing two separate services.
4. Azure Cognitive Services
Azure Cognitive Services provides AI-based analysis across speech, language, vision, and decision applications. Entity Recognition is part of their Language service, detecting both common and custom entities in text or transcribed audio.
While Azure offers a free tier for testing, the initial setup can be complex, particularly when combining speech recognition with entity detection. The platform suits enterprises already invested in the Azure ecosystem.
5. TextRazor
The TextRazor API extracts entities and relationships from documents, focusing on understanding "who, what, why, and how" from text. Their Named Entity Recognition identifies people, places, companies, and uses disambiguation techniques to improve accuracy, though performance typically trails specialized NER providers.
Pricing starts at $200 monthly for 6,000 daily requests, positioning it for medium-scale applications rather than high-volume processing.
6. Allganize
Allganize provides an NLU API designed for customer interaction analysis. Their Named Entity Recognition automatically classifies keywords and extracts information about people, places, and events from customer communications.
Their Growth tier includes a free trial, then costs $0.02 per call for up to 10,000 calls, making it cost-effective for customer service applications with moderate volume.
Getting started with NER API integration
Integrating an NER API into your application follows a straightforward process. While implementation details vary between providers, the workflow generally follows these steps:
Step 1: Obtain API credentials
Sign up with your chosen provider to get an API key or authentication token. Most providers offer free tiers or trial credits for testing.
Step 2: Prepare your text data
Ensure your text is UTF-8 encoded. If working with audio or video content, youll first need transcription using a speech-to-text service.
Step 3: Make the API request
With AssemblyAI, you enable Entity Detection on an audio file by setting the entity_detection parameter to true in a POST request to the /v2/transcript endpoint. Here's a typical request structure:
For a hands-on example of entity detection with audio files, check out the tutorial below or explore AssemblyAI's documentation for comprehensive code samples.
Entity detection tutorial
Want to learn how to perform Entity Detection or Named Entity Recognition on audio files in Python? This tutorial walks through the complete process:
Frequently asked questions about Named Entity Recognition APIs
What is the difference between NER and entity linking?
NER identifies and categorizes entities like "Apple" as an "ORGANIZATION", while entity linking goes further by disambiguating which specific Apple (company vs. fruit) and connecting it to a knowledge base entry.
How is NER used with speech-to-text?
NER processes transcribed audio to identify entities like speaker names, companies, or locations mentioned in conversations, commonly used in call analytics and conversation intelligence platforms.
Can I detect custom entities with an API?
Yes, advanced NER APIs from providers like Google and Azure support custom entity training for industry-specific terminology, though this typically requires labeled training examples and additional costs.
Ready to add entity detection to your application? Try AssemblyAI's API free and extract entities from audio or text with industry-leading accuracy.
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