AI Chat Comparison 2026: ChatGPT, Claude, Gemini, Copilot and 6 More (Pricing & Free Plans)

When choosing an AI chat tool, many people are unsure about pricing structures, the availability of free plans, output quality, and supported platforms. Each tool has its own strengths, making it difficult to judge based on a single feature alone.

This article compares the pricing, free plan availability, Japanese support, and platforms of 10 major tools based on AIpedia data (as of November 2026). It also outlines each tool's strengths and weaknesses and explains key points for choosing a tool suited to specific business scenarios.

Finally, we provide recommendations by goal, tips on how to choose without making mistakes, and an FAQ. Check your concerns before implementation and find the AI assistant that best fits your needs.

What is AI Chat? What It Can Do and What to Know Before Choosing

AI chat refers to conversational AI assistants that respond to natural language questions or instructions by handling tasks such as writing, organizing information, and generating code. Unlike simple search engines, they understand the context of your input and return specific answers or suggestions. For example, ChatGPT supports image and video generation, while Claude can process up to 1 million tokens of text at once.

• Writing and editing: Supports daily writing tasks, such as drafting emails or reports, summarizing existing text, and adjusting tone.
• Information organization and analysis: Reads web search results or uploaded files to extract key points or perform data-based analysis.
• Code generation and assistance: Provides coding features for writing code in programming languages, suggesting bug fixes, or understanding overall project structure.
• Multilingual support and translation: Performs context-aware translation between multiple languages, including Japanese.
• Multimodal processing: Handles input and output beyond text, including images, audio, and video, enabling comprehensive task processing that includes visual information.

When choosing a tool, first check the free usage limits. Pricing structures vary widely, from services like DeepSeek or Tenbin AI byGMO that are completely free or low-cost, to paid plans offering advanced features. Japanese language quality is also a key comparison point. According to AIpedia data, ChatGPT offers top-tier accuracy in Japanese text generation, while Grok 4 and Mistral AI may slightly lag behind ChatGPT and Claude in terms of naturalness and accuracy in Japanese.

Additionally, you need to confirm whether the tool is for individuals or businesses, and what environments it supports. Copilot (Microsoft) and Microsoft 365 Copilot are deeply integrated with Office products, specializing in business efficiency. On the other hand, Sider AI operates as a browser sidebar, allowing easy use while viewing web pages. It is important to compare each tool's supported platforms (Web, iOS, Android, etc.) and its ability to integrate with organizational data to select the one that fits your workflow.

Comparison of Top 10 Tools (Pricing, Japanese Support, Platforms)

Tool	AIpedia rating	Main plans	Japanese support	Platforms
ChatGPT	4.5	free plan (GPT-5.2 limited) / Go $8/month (¥1,500) / Plus $20/month (GPT-5.4, Sora 2, etc.)	Supported	Web, iOS, Android, macOS, and others
Claude	4.5	free plan (limited) / Pro $17/month (annual billing) / $20/month (monthly billing) (Opus 4.6, priority access) / Max 5x $100/month	Supported	Web, iOS, Android, macOS, and others
Gemini	4.3	free plan (Gemini 2.5 Flash limited) / AI Plus ¥1,200/month / AI Pro ¥2,900/month (Gemini 3.1 Pro, 2TB storage)	Supported	Web, iOS, Android
Copilot (Microsoft)	4.1	Free (basic features) / Copilot Pro ¥3,200/month (priority access, Office integration) / Microsoft 365 Copilot $30/user/month (for businesses)	Supported	Web, Windows, macOS, iOS, and others
Microsoft 365 Copilot	4.3	Microsoft 365 Copilot $30/user/month (annual billing / ¥4,497, separate Microsoft 365 license required)	Supported	Web, Windows, Mac, iOS, and others
Grok 4	4.3	X Premium+ approx. $22/month (includes Grok 4) / Grok standalone subscription $30/month / SuperGrok $300/month (top-tier access)	Supported (some UI in English, Japanese responses available)	Web, X (Twitter), iOS, Android, and others
DeepSeek	4.2	Completely free (Web version) / API $0.27/1 million input tokens	Supported (Japanese conversation possible)	Web, iOS, Android, API
Mistral AI	4.2	Le Chat free / Le Chat Pro €14.99/month / API pay-as-you-go (Mistral Small $0.1/1 million tokens to Large $2/1 million tokens)	Supported	Web, iOS, Android, API
Tenbin AI byGMO	4.1	Free ¥0 (basic features) / Plus ¥970/month (file and web search support) / Biz ¥1,100/user/month + pay-as-you-go (for businesses)	Fully supported (Made in Japan)	Web
Sider AI	4.3	free plan (30 queries/day) / Basic $8.99/month / Pro $12.99/month	Supported	Chrome extension, Edge extension, Safari extension, macOS, and others

Ratings are based on a 5-point scale by the AIpedia editorial team. Pricing and plans may change. Please check the latest information on each tool's official website before subscribing.

Features, Pricing, and Best Use Cases for 10 Tools

1. ChatGPT

ChatGPT is a conversational AI assistant developed by OpenAI. It handles text generation, code creation, and data analysis, and can also generate images and videos within a single platform. As of 2026, it features the GPT-5.4 Thinking model to handle complex reasoning tasks.

• Strengths: It offers robust multimodal support for text, images, audio, and video, allowing you to process a wide range of tasks within a single chat interface. Additionally, hundreds of thousands of custom GPTs are available, enabling immediate access to specialized assistants tailored to specific needs.
• Strengths: It delivers high accuracy in Japanese text generation, producing natural expressions suitable for business emails and proposals. Furthermore, Codex integrates with GitHub repositories to automate development workflows from issue creation to pull request generation.
• Strengths: The Go plan ($8/month) provides affordable access to high-performance models. It also features high-quality voice conversation capabilities in the mobile app.
• Things to note: Ads are displayed on the free plan and the Go plan. The free plan has strict message limits, approximately 10 messages per 5 hours. Also, in terms of long-context understanding and consistency, it may fall short compared to Claude, which handles 1 million tokens.
• Things to note: The accuracy of generated information is not guaranteed, and there is a risk of hallucinations (generating incorrect information). If using outputs for critical decisions, always verify with primary sources or experts.

Pricing: Free plan (GPT-5.2 limited) / Go $8/month (¥1,500) / Plus $20/month (GPT-5.4, Sora 2, etc.) / Pro $200/month (top-tier models, unlimited access) / Team $25/user/month / Enterprise (contact sales)

Best for: Individuals who want to handle diverse functions like image generation and data analysis with a single tool. Business professionals who prioritize natural Japanese writing. Also suitable for individuals or teams looking to streamline workflows using custom GPTs.

View detailed features, pricing, and FAQ for ChatGPT

2. Claude

Claude is a conversational AI assistant developed by Anthropic. It features an ultra-long context window of 1 million tokens, allowing it to process text equivalent to several books at once. It is also known for its high accuracy in coding assistance and complex reasoning tasks.

• Strengths: With a 1-million-token context window, it can read and analyze text from multiple books or large codebases in one go.
• Strengths: Equipped with Claude Code, it understands the entire project codebase to generate, edit, and debug code based on natural language instructions.
• Strengths: It is praised for its safety design based on Constitutional AI and its honest approach to explicitly stating uncertain information.
• Strengths: The Artifacts feature allows you to generate and preview code, HTML, SVG, and diagrams on the spot. The Projects feature lets you load and use multiple documents together.
• Things to note: It lacks image generation capabilities, so creating visual content requires using other tools alongside it.
• Things to note: The free plan has somewhat strict limits on message submissions. The Max plan ($100–200/month) is expensive for individuals. Real-time web search is also more limited compared to ChatGPT or Gemini.

Pricing: Free plan (limited) / Pro $17/month (annual billing) · $20/month (monthly billing) (Opus 4.6, priority access) / Max 5x $100/month / Max 20x $200/month / Team $25/user/month (annual billing) · $30 (monthly billing) / Enterprise (contact sales)

Best for: Engineers and business professionals who perform long-form document analysis or coding tasks that prioritize accuracy. It is also suitable for corporate decision-makers who want to adopt AI with a focus on safety. However, if you primarily use image generation or real-time search features, we recommend comparing it with other tools.

View details on Claude's features, pricing, and FAQ

3. Gemini

Gemini is a multimodal AI developed by Google DeepMind. It is characterized by its ability to integratively understand text, images, audio, and video. It also integrates deeply with Google products, contributing to improved business efficiency.

• Strengths: Integrates deeply with Google Workspace, including Gmail, Docs, Sheets, and Slides. Because it is connected to Google Search, it can provide answers while looking up the latest information.
• Strengths: A 1-million-token context window allows processing large amounts of data at once. It can natively understand videos up to 1 hour long.
• Strengths: The NotebookLM feature lets you create an AI assistant based on your own documents. It also supports outputting summaries in podcast format.
• Things to note: Japanese creative writing is considered slightly inferior to ChatGPT.
• Things to note: Image generation (ImageFX) is still developing compared to DALL-E 3 and Midjourney. The top-tier AI Ultra (¥36,400/month) is very expensive.

Pricing: Free plan (Gemini 2.5 Flash limited) / AI Plus ¥1,200/month / AI Pro ¥2,900/month (Gemini 3.1 Pro, 2TB storage) / AI Ultra ¥36,400/month (unlimited all features, 30TB, includes YouTube Premium) / Business $24/user/month / Enterprise $36/user/month

Best for: People who use Google Workspace in their work. It is suitable for those who prioritize cost-performance and want to obtain real-time information or perform analysis based on their own documents.

View details on Gemini's features, pricing, and FAQ

4. Copilot (Microsoft)

Copilot (Microsoft) is an AI assistant developed by Microsoft based on its partnership with OpenAI. It is natively integrated into Windows 11, the Edge browser, and Office products, allowing you to use it without installing additional apps or creating accounts. It supports a wide range of tasks from daily assistance to business efficiency, characterized by its seamless operation within the Microsoft ecosystem.

• Strengths: Integrated by default into Windows 11, Edge, and Office products, allowing you to use AI without leaving the app you are working in. You can launch it by clicking the taskbar icon and issue OS setting changes using natural language.
• Strengths: The free plan includes GPT-4o-based AI chat and image generation via DALL-E 3. Because it is integrated with Bing search, you can get answers that reference real-time web information.
• Strengths: Upgrading to Copilot Pro unlocks AI features within Office products like Word and Excel. For businesses, options include data protection, leveraging internal organizational data via Microsoft Graph, and creating custom copilots with Copilot Studio.
• Things to note: As a standalone AI tool, its extensibility is more limited compared to ChatGPT or Claude. It lacks mechanisms for custom AIs like GPTs or coding agents like Codex.
• Things to note: It may underperform other tools in creative writing or complex reasoning tasks. Additionally, the benefits of OS integration are limited for Mac and Linux users.

Pricing: Free (basic features) / Copilot Pro ¥3,200/month (priority access, Office integration) / Microsoft 365 Copilot $30/user/month (for businesses)

Best for: Business professionals using Windows PCs who create documents in Office and browse with Edge. It is suitable for individuals who want to use an AI assistant without additional costs, and for business organizations that prioritize security and compliance.

View detailed features, pricing, and FAQ for Copilot (Microsoft)

5. Microsoft 365 Copilot

Microsoft 365 Copilot is an assistant for businesses that integrates AI into apps like Word, Excel, PowerPoint, Outlook, and Teams. By leveraging organizational data (Microsoft Graph), it supports tasks such as document creation, data analysis, and meeting summaries. While the name is transitioning to Microsoft Copilot starting in 2026, the pricing page still uses the traditional name.

• Strengths: Use AI directly within familiar Office apps and automate workflows that span across applications. In Excel, you can generate functions and charts using natural language. In Teams, it performs automatic meeting summaries and extracts action items.
• Strengths: Complies with enterprise security and compliance standards such as GDPR and ISO 27001. Prompts, responses, and organizational data are not used to train the underlying LLM, providing peace of mind regarding internal information management.
• Things to note: In addition to the $30 monthly fee, a separate Microsoft 365 license is required. Also, note that answer quality can vary significantly depending on the state of your organization's data preparation.

Pricing: For businesses, it is $30 per user per month (annual billing: ¥4,497). Copilot Business, for organizations with up to 300 users, is $21/user/month (¥3,148), discounted to $18 through the end of 2026. For individuals, it is included in Microsoft 365 Personal ($9.99/month, ¥2,130) or Family, but organizational data cannot be used.

Best for: Ideal for business users who use Office apps daily and want to leverage data across their organization. It is also suitable for those looking to deploy it confidently in environments with high security requirements, or for professionals prioritizing the efficiency of routine tasks. Please check the official website for the latest pricing and features.

6. Grok 4

Grok 4 is the fourth-generation model in the Grok series developed by xAI. Its key feature is direct access to the real-time timeline on X (formerly Twitter). It can provide answers while referencing the latest news and trends.

• Strengths: Thanks to real-time integration with X, it can immediately reflect discussions and breaking news from social media in its responses.
• Strengths: Supports long contexts of over 1M tokens and offers enhanced reasoning performance.
• Strengths: Uses an OpenAI-compatible API, making it easy to reuse existing codebases. Image generation (Aurora) and video generation (Grok Video) are also available within the same service.
• Things to note: Responses may sometimes feel more biased compared to other AI assistants.
• Things to note: Japanese naturalness and enterprise-oriented features may be weaker compared to tools from other companies.

Pricing: X Premium+ approx. $22/month (includes Grok 4) / Standalone Grok subscription $30/month / SuperGrok $300/month (top-tier access) / API (x.ai) pay-as-you-go

Best for: Ideal for those whose main work involves social media marketing or news research. It suits users seeking speed in analyzing the latest trends, or developers looking to minimize API migration costs. However, if you prioritize creating solid business documents, please compare it with other tools.

View detailed features, pricing, and FAQ for Grok 4

7. DeepSeek

DeepSeek is a high-performance AI chat assistant developed by DeepSeek, a Chinese company. It features the R1 reasoning model and delivers strong performance in tasks such as mathematics and coding. It is also notable for being open-source.

• Strengths: The web version is completely free to use, and API pricing is very low.
• Strengths: High reasoning capability, supporting math problem solving and code generation.
• Things to note: As a service originating from China, it may raise concerns regarding data privacy.
• Things to note: Japanese quality may be inferior to GPT-4 in some cases, and response times may slow down during server congestion.

Pricing: Completely free (Web version) / API $0.27/1 million input tokens

Best for: Ideal for those who want to handle technical tasks like reasoning and programming while keeping costs low. However, if you prioritize Japanese naturalness or data management, you need to compare it with other tools.

View detailed features, pricing, and FAQ for DeepSeek

8. Mistral AI

Mistral AI is a French AI company that provides open-source models as well as models like Mistral Large 2 and Codestral for coding. Its chat service, Le Chat, offers features such as web search and image generation.

• Strengths: Le Chat is available for free, offering high cost-efficiency.
• Strengths: Provides an OpenAI-compatible API, making migration to existing environments easy.
• Strengths: Complies with the EU AI Act and allows running open-source models in your own environment. It also supports on-premises and VPC deployment.
• Things to note: Japanese accuracy may be slightly inferior to GPT-5 or Claude in some cases. Le Chat’s features are not as comprehensive as those of ChatGPT.

Pricing: Le Chat free / Le Chat Pro €14.99/month / API pay-as-you-go (Mistral Small $0.1/1 million tokens to Large $2/1 million tokens) / Enterprise (contact sales)

Best for: Individuals who want to use multilingual AI while keeping costs low, or business managers who prioritize EU regulatory compliance.

9. Tenbin AI byGMO

Tenbin AI byGMO is a generative AI platform provided by the GMO Internet Group. It runs up to six large language models simultaneously, allowing you to compare answers on a single screen. It also supports simultaneous comparison of image generation AI.

• Strengths: You can compare responses from multiple AI models in one batch.
• Strengths: The “Tenbin Judge” feature allows AI to analyze and integrate answers.
• Strengths: Basic features are available for free on the Free plan.
• Things to note: There are credit limits for using advanced models.
• Things to note: API integration is only supported on the Biz plan.

Pricing: Free ¥0 (basic features) / Plus ¥970/month (file and web search support) / Biz ¥1,100/user/month + pay-as-you-go (for businesses)

Best for: Individuals who want to compare outputs from multiple AIs to select the optimal solution. It is also suitable for individuals who want to try basic features for free, and for businesses that require security management.

View details on Tenbin AI byGMO features, pricing, and FAQ

10. Sider AI

Sider AI is an AI assistant that resides as a sidebar in browsers like Chrome or Edge. You can switch between multiple AI models such as ChatGPT, Claude, and Gemini with one click. Its key feature is the ability to instantly summarize web pages, translate text, and create content within the browser. It has over 10 million users.

• Strengths: High convenience due to seamless switching between multiple AI models and processing directly within the browser.
• Strengths: Supports summarizing YouTube videos and reading PDFs, and includes a group chat feature that lets you ask the same question to multiple AIs to compare answers.
• Things to note: The free plan is limited to 30 queries per day.
• Things to note: There may be limits on the number of uses for each AI model, making it unsuitable for advanced customization.

Pricing: Free plan (30 queries/day) / Basic $8.99/month / Pro $12.99/month / Elite $19.99/month / Team $18/user/month

Best for: Individuals who want to compare and evaluate multiple AI models while working in a browser. It is suitable for business professionals who frequently summarize web pages or translate text.

Recommendations by Goal

Goal	Recommended	Reason
Want to try it for free first	DeepSeek	The web version is completely free, allowing you to use high-performance answers from the R1 reasoning model.
Prioritize Japanese text generation	ChatGPT	AIpedia's data rates its Japanese text generation as top-tier among AI chat tools.
Process long documents or large amounts of data	Claude	With a 1 million token context window, it can process the content of several books at once.
Improve work efficiency within Office apps	Microsoft 365 Copilot	It directly supports document creation and data analysis within familiar apps like Word and Excel.
Use it together with Google Workspace	Gemini	It integrates with Google Workspace such as Gmail, Docs, and Sheets. Paid plans start from AI Plus (¥1,200/month).
Look up the latest topics on X	Grok 4	It can provide answers by referencing the real-time timeline of X (formerly Twitter).
Quickly summarize and translate in the browser	Sider AI	It operates as a browser extension, allowing you to instantly execute summarization and translation of web pages.
Compare multiple AI models	Tenbin AI byGMO	It has a feature that allows you to compare answers from up to 6 AI models simultaneously on one screen.
Use APIs at low cost	Mistral AI	It offers an OpenAI-compatible API with pay-as-you-go pricing, which makes migration easy.

The above reflects general trends based on data. The optimal tool varies depending on actual business workflows and security requirements. We recommend checking the latest pricing structures and feature limitations on each company's official website before implementation.

How to Choose Without Regrets

Determine your plan based on purpose and frequency

If you use the tool infrequently or want to keep costs low, start with low-cost options such as Copilot (Microsoft) free features or the ChatGPT Go plan ($8/month). On the other hand, if you frequently perform advanced reasoning or process large amounts of data, consider paid plans that include access to higher-tier models, such as Claude Pro or Gemini AI Pro (¥2,900/month).

Check Japanese support and platforms

If you prioritize writing in Japanese, ChatGPT is the top candidate, as AIpedia data rates its Japanese accuracy as top-tier. Also verify the supported devices. Gemini supports Web, iOS, and Android, while Tenbin AI byGMO supports Web only. Sider AI centers on browser extensions but also works on macOS, Windows, iOS, and Android. Tenbin AI byGMO is made in Japan, and its interface is in Japanese.

Evaluate integration with existing tools

If you use Google Workspace, Gemini’s native integration is a major advantage. For businesses using Microsoft 365 for work, Microsoft 365 Copilot has a low barrier to adoption because it lets you use AI directly within Word and Excel. Checking compatibility with your existing environment helps reduce additional learning costs.

Compare free tiers and usage limits

The DeepSeek web version is completely free, but response times may slow down during server congestion. In contrast, the free plans for ChatGPT and Claude have message limits, and ads are displayed on both the ChatGPT free plan and the Go plan. Sider AI also has a limit of 30 queries per day on its free tier, so you need to assess when to switch to a paid plan based on your usage frequency.

Align for-business features with security requirements

If you are considering adoption not just for individual use but for teams or businesses, data management and permission settings are critical. Microsoft 365 Copilot can leverage organizational data across services, but it requires a separate license. Mistral AI complies with the EU AI Act and supports on-premises and VPC deployments. Please check the official website for the latest pricing and features.

FAQ

Q. Which AI chat tools can be used for free?

Major tools like ChatGPT, Claude, and Gemini offer free plans. The web version of DeepSeek is completely free to use. Copilot (Microsoft) also allows basic features for free. Additionally, there are Mistral AI's Le Chat, the Free plan from Tenbin AI byGMO, and Sider AI's free plan (30 queries per day).

Q. Which tools are best at creating Japanese text?

ChatGPT is rated as top-tier among AI chats for the accuracy of Japanese text generation. Claude is also known for high answer accuracy and its stance on explicitly stating uncertain information. Gemini is considered slightly inferior to ChatGPT in creative Japanese writing.

Q. Which tool is suitable for processing long documents?

Claude has a 1 million token context window, allowing it to process several books at once. Gemini also supports 1 million tokens, and Grok 4 supports contexts of 1M tokens or more. ChatGPT is said to have instances where it falls short of Claude in maintaining consistency in long texts.

Q. What should be noted when using these tools for businesses or teams?

Microsoft 365 Copilot costs $30/user/month on top of a Microsoft 365 license. The ChatGPT Team plan is $25/month per user. Answer quality may vary depending on the organization's data readiness, so prior verification is important.

Q. How can I use and compare multiple AI models simultaneously?

Tenbin AI byGMO is a platform that allows simultaneous execution and comparison of up to 6 AI models. Sider AI also allows switching between multiple models as a browser extension. It is effective to not limit yourself to a single tool but to use different tools according to your needs.

Q. What is the difference between Copilot (Microsoft) and Microsoft 365 Copilot?

Copilot (Microsoft) is an AI assistant integrated into Windows, Edge, and Office, which individuals can start using for free. The paid Copilot Pro costs ¥3,200/month. Microsoft 365 Copilot is for businesses, requiring $30/month per user (annual billing) in addition to a Microsoft 365 license. A major difference is that it can use organizational data across Microsoft Graph.

Q. Is it safe to input work-related information?

Data handling varies by tool. Microsoft 365 Copilot states that prompts, responses, and data via Microsoft Graph are not used for training the underlying LLMs. DeepSeek is a Chinese service, so there are concerns about data privacy. Before entering company information, please check your internal regulations as well as each tool's terms of use and data handling policies.

Summary

This article compared 10 major AI chat tools, including ChatGPT and Claude. Each tool differs in the availability of a free plan, monthly pricing, Japanese support accuracy, and platforms. They also vary in long-form processing capabilities, image generation features, and integration with specific business applications.

When adopting a tool, it is important to evaluate options based on your company's usage environment, budget, and desired answer quality, rather than just the number of features. Options for how you use the tools are expanding, such as trying a free plan before moving to a paid plan or utilizing browser extensions. Please check each official website for the latest pricing structures and feature additions.

• Broad task coverage and Japanese accuracy: ChatGPT (integrates image and video generation with reasoning features)
• Long-form processing and coding: Claude (supports 1 million tokens with a focus on accuracy)
• Easy use in the browser: Sider AI (switch between multiple models with one click)

View all AI chat and assistant tools (25 items)