21 Best Open Source Chatbot Platforms to Try in 2025

The world of chatbots has exploded, offering businesses and individuals powerful tools for automation, customer engagement, and streamlined workflows.

While proprietary chatbot platforms exist, open-source options provide unparalleled flexibility, customization, and control.

Considering a Managed Solution? Skip the Hassle with Chatbase

While open-source platforms offer incredible control and customization, they often require significant technical expertise and resources for setup, hosting, and maintenance.

If you're looking for a powerful yet user-friendly solution without the complexities of managing your own infrastructure, a managed platform like Chatbase might be the perfect fit.

Chatbase provides a no-code environment for building and deploying AI chatbots, powered by advanced language models like GPT-4 or Claude or Gemini.

It's not open-source, but it offers a compelling alternative for businesses that prioritize ease of use and rapid deployment.

With Chatbase, you can train your chatbot on your own data (websites, documents, etc.) and customize its appearance and behavior to match your brand.

Why Choose Chatbase?

No-Code Simplicity: Build and deploy chatbots without writing a single line of code, thanks to Chatbase's intuitive visual interface.
Hassle-Free Hosting: Focus on creating great conversational experiences, while Chatbase handles all the technical infrastructure, including hosting, scaling, and maintenance.
Faster Time to Market: Get your chatbot up and running quickly, without the delays often associated with open-source setup and configuration.
Focus on Your Business: Instead of managing servers and code, dedicate your time to refining your chatbot's personality, knowledge base, and user experience.
Free Trial: You can test the waters with Chatbase by signing up for their free trial, and experience its capabilities before committing.

While Chatbase isn't open-source, it provides a compelling alternative that eliminates the technical complexities, allowing you to launch sophisticated AI chatbots with minimal effort.

It's a great option for businesses that value speed, ease of use, and a managed solution that lets them focus on their core objectives.

Now, you can proceed with the list of 21 open-source chatbot platforms:

1. Rasa

Website: https://rasa.com/

Rasa is a leading open-source framework built in Python, renowned for its advanced Natural Language Understanding (NLU) and dialogue management capabilities. It allows developers to create sophisticated, context-aware chatbots that can handle complex, multi-turn conversations. Rasa offers granular control over the chatbot's behavior and integrates well with various messaging channels.

Why use Rasa?

Advanced NLU: Fine-tune your bot's understanding of user intent and context with its customizable NLU pipeline.
Flexible Dialogue Management: Design intricate conversation flows using machine learning and rule-based approaches.
Full Control: Modify and extend the framework to fit your specific needs, making it ideal for complex or unique use cases.

2. Botpress

Website: https://botpress.com/

Botpress is a user-friendly, open-source platform that bridges the gap between developers and non-technical users. It features a visual flow builder for designing conversations and a built-in NLU engine. Botpress is written in TypeScript and offers a modular architecture, making it easy to extend and customize.

Why use Botpress?

Visual Interface: The drag-and-drop interface simplifies chatbot development, making it accessible to a wider range of users.
Modular Design: Easily add or remove functionalities with its extensive library of modules and integrations.
Hybrid Approach: Combine visual development with code when needed, providing flexibility for both simple and complex projects.

3. Microsoft Bot Framework

Website: https://dev.botframework.com/

The Microsoft Bot Framework is a comprehensive, open-source SDK for building enterprise-grade chatbots. It supports various programming languages and integrates seamlessly with Microsoft Azure services, including LUIS (Language Understanding Intelligent Service). This framework is highly scalable and suitable for complex, multi-channel deployments.

Why use Microsoft Bot Framework?

Enterprise-Ready: Designed for large-scale deployments with robust security and scalability features.
Azure Integration: Leverage the power of Azure's AI and cloud services for enhanced capabilities.
Multi-Channel Support: Deploy your bot across a wide range of platforms, including web, mobile, and enterprise applications.

4. Botkit

Website: https://botkit.ai/

Acquired by Microsoft, Botkit is a developer-friendly, open-source toolkit for creating chatbots, apps, and custom integrations for major messaging platforms. It offers a visual conversation builder and a wide range of plugins, making it a versatile choice for various use cases.

Why use Botkit?

Developer-Centric: Provides extensive tools and SDKs to streamline the development process.
Visual Conversation Builder: Simplifies the creation of complex dialogue flows.
Strong Community Support: Benefit from a large community of developers and a wealth of online resources.

5. OpenDialog

Website: https://opendialog.ai/

OpenDialog is an open-source, enterprise-grade conversational AI platform that emphasizes flexibility, scalability, and ease of integration. It's particularly well-suited for regulated industries like healthcare and finance, offering robust security and compliance features.

Why use OpenDialog?

Highly Regulated Industries: Designed to meet the stringent security and compliance requirements of sectors like healthcare and finance.
Flexible Deployment: Deploy on-premise or in the cloud, providing control over your data and infrastructure.
Advanced Dialogue Management: Create sophisticated, context-aware conversations that adapt to user needs.

6. Claudia Bot Builder

Website: https://www.npmjs.com/package/claudia-bot-builder

Claudia Bot Builder is a lightweight, open-source library that simplifies the creation of chatbots for platforms like Facebook Messenger, Telegram, and Slack. It's designed to remove boilerplate code and streamline the development process.

Why use Claudia Bot Builder?

Simplified Development: Focus on your bot's logic rather than platform-specific configurations.
Serverless-Ready: Optimized for deployment on serverless platforms like AWS Lambda.
Easy Integration: Quickly connect your bot to multiple messaging platforms.

7. Tock

Website: https://doc.tock.ai/

Tock is an open-source conversational AI platform that supports both voice and text interactions. It's designed to be platform-agnostic and can be deployed on various channels, including web, mobile, and IoT devices.

Why use Tock?

Multimodal Support: Build bots that can interact through voice, text, and other modalities.
Technology Agnostic: Create bots once and deploy them across multiple platforms, from messaging apps to smart speakers.
Flexible Architecture: Customize and extend the platform to fit your specific needs.

8. BotMan

Website: https://botman.io/

BotMan is a framework-agnostic, open-source PHP framework for chatbot development. It allows developers to write chatbot logic once and connect it to various messaging services, including Slack, Telegram, and Microsoft Bot Framework.

Why use BotMan?

PHP-Based: Ideal for developers already working within the PHP ecosystem.
Framework Agnostic: Integrates with your existing PHP codebase, regardless of the framework used.
Multi-Platform Support: Deploy your bot on a wide range of messaging services.

9. Bottender

Website: https://bottender.js.org/

Bottender is an open-source JavaScript framework for building conversational user interfaces. It's built on top of Messaging APIs and offers a functional, declarative approach to defining conversation flows.

Why use Bottender?

JavaScript Focused: Perfect for developers comfortable with JavaScript and React.
Cross-Platform Development: Build once and deploy on web, mobile, and messaging apps.
Modern Development Practices: Leverages functional programming concepts for cleaner, more maintainable code.

10. DeepPavlov

Website: https://deeppavlov.ai/

DeepPavlov is an open-source conversational AI framework built on TensorFlow and Keras. It provides a wide range of pre-trained models and components for building complex dialogue systems.

Why use DeepPavlov?

Research-Oriented: Leverages cutting-edge research in deep learning and NLP.
Pre-trained Models: Access a library of pre-trained models for various NLP tasks.
Modular and Extensible: Customize and extend the framework to fit your research or application needs.

11. Llama

Website: https://ai.meta.com/llama/

Llama is a family of large language models (LLMs) released by Meta AI. It's available in various sizes, offering flexibility for different computational needs and use cases. Llama models are open-source, enabling customization and experimentation.

Why use Llama?

Powerful LLMs: Access state-of-the-art language models for advanced text generation and understanding.
Open-Source and Free: Use, modify, and distribute Llama models without licensing fees.
Scalable Solutions: Choose the model size that best suits your performance requirements and resource constraints.

12. Wit.ai

Website: https://wit.ai/

Acquired by Facebook, Wit.ai is a free, open-source NLP platform that simplifies the creation of voice and text-based chatbots. It offers an intuitive API and supports multiple languages.

Why use Wit.ai?

Easy to Use: Get started quickly with a user-friendly interface and well-documented API.
Strong NLP Capabilities: Leverage Facebook's NLP expertise for accurate intent recognition and entity extraction.
Free for Developers: Access the platform's core features without any cost.

13. GPT-2

Website: https://openai.com/research/gpt-2-1-5b-release

GPT-2, a predecessor to the more recent GPT models, is a powerful language model developed by OpenAI. While not specifically a chatbot framework, it can be used as a foundation for building conversational agents.

Why use GPT-2?

Strong Language Generation: Create highly coherent and contextually relevant text.
Open-Source Availability: Access and fine-tune the model for your specific chatbot needs.
Foundation for Innovation: Use GPT-2 as a starting point for developing novel conversational AI applications.

14. ChatterBot

Website: https://chatterbot.readthedocs.io/

ChatterBot is a Python-based, open-source library that simplifies the creation of chatbots. It uses machine learning to generate responses based on a collection of known conversations.

Why use ChatterBot?

Easy to Learn: A great starting point for developers new to chatbot development.
Language Independent: Train your bot on conversations in any language.
Adaptable: The bot learns and improves its responses over time based on interactions.

15. BotKit

Website: https://github.com/howdyai/botkit

Botkit is a popular open-source developer tool for building chatbots, apps, and custom integrations for major messaging platforms. It provides a visual conversation builder and a wide range of plugins. (Note: Botkit is maintained by Microsoft, and a part of the Microsoft Bot Framework)

Why use Botkit?

Visual Conversation Builder: Simplify the design of complex conversation flows.
Extensive Plugin Ecosystem: Add functionalities and integrations with ease.
Large Community: Benefit from a strong community of developers and a wealth of online resources.

16. Golem

Website: https://golem.ai/

Golem is a Python-based framework for building chatbots with a focus on natural language understanding. It provides tools for intent recognition, entity extraction, and dialogue management.

Why use Golem?

Python-Focused: Ideal for developers comfortable with Python.
Linguistic Approach: Leverages linguistic principles for more accurate language understanding.
Open-Source and Customizable: Modify and extend the framework to meet your specific requirements.

17. Typebot

Website: https://typebot.io/

Typebot is a no-code chatbot builder that allows you to create conversational forms and chatbots visually. It's an excellent choice for non-developers who want to build simple to moderately complex chatbots.

Why use Typebot?

No-Code Interface: Build chatbots without writing any code.
Visual Builder: Drag and drop elements to create conversation flows.
Easy Integration: Embed your chatbot on your website or use it within messaging platforms.

18. QnA Maker

Website: https://learn.microsoft.com/en-us/azure/ai-services/language-service/question-answering/overview

QnA Maker, a part of Microsoft's Azure AI services, allows you to create a chatbot from existing FAQs or documents. It's ideal for quickly building knowledge-based chatbots. Now it is a part of the Azure AI Language service.

Why use QnA Maker?

Rapid Development: Build a chatbot in minutes from your existing content.
Easy to Maintain: Update your chatbot's knowledge base without complex coding.
Azure Integration: Leverage other Azure services to enhance your chatbot's capabilities.

19. Langchain

Website: https://www.langchain.com/

LangChain is a framework for developing applications with large language models. It's not a chatbot platform itself, but it provides the building blocks for creating sophisticated conversational agents.

Why use LangChain?

LLM Integration: Easily integrate with various language models, including those from OpenAI and Anthropic.
Modular Design: Combine different components to build complex language-based applications.
Open-Source and Flexible: Customize and extend the framework for your specific needs.

20. Haystack

Website: https://haystack.deepset.ai/

Haystack is an open-source framework for building search systems, including question-answering and conversational search. It's designed for developers who want to create powerful search experiences.

Why use Haystack?

Advanced Search Capabilities: Build chatbots that can answer complex questions based on your data.
Modular Architecture: Choose the components that fit your needs, from document stores to retrievers and readers.
Open-Source and Customizable: Tailor the framework to your specific search and conversational AI requirements.

21. Juji

Website: https://juji.io/

Juji is a no-code AI chatbot platform that specializes in creating "cognitive AI assistants." These chatbots are designed to engage users in empathetic and personalized conversations.

Why use Juji?

No-Code Development: Build and deploy chatbots without writing code.
Empathy and Personalization: Create chatbots that understand and respond to user emotions.
Advanced NLP: Leverage Juji's proprietary NLP engine for nuanced conversations.

Choosing the right open-source chatbot platform depends on your specific needs, technical expertise, and the complexity of your project.

Consider factors like ease of use, customization options, integration capabilities, community support, and scalability when making your decision.

By exploring these platforms, you can find the perfect foundation for building your next-generation conversational AI in 2025 and beyond.