"I asked ChatGPT, but it would have been faster to look it up online..." Have you ever had that experience?
As of March 2026, major AI tools such as ChatGPT, Perplexity, and Gemini are each equipped with search and research functions. However, if you think, "They're all the same, right?" and use them randomly, you'll end up being swayed by weak answers and outdated information.
In this article, we will provide an easy-to-understand explanation of the correct way to use AI when investigating things, including the characteristics of each tool, its areas of expertise, and the range of tools that can be used for free.
In the first place, there are two types of AI "investigations"
The first thing you should know is that there are two main patterns when asking something to AI.
Pattern 1: Answer from AI learning data (knowledge-based type)
This is a pattern in which the AI answers based on information learned in the past. This is suitable for asking questions that are already established, such as "Teach me how to manipulate lists in Python" or "What is the basic process of filing a tax return?"
Pattern 2: Search the internet in real time and answer (web search type)
In this pattern, AI searches the Internet on the spot and answers based on the latest information. It is necessary when looking up Freshness is the key to information, such as ``What's the exchange rate today?'' ``What's the information about iOS 26 bugs?''
If you confuse this, you will tend to think, ``I'm only getting a weak answer...'' Each tool is different in which of these two it is good at.
Perplexity is the best for "research with sources"
Perplexity AI is, roughly speaking, a tool that uses AI to search the internet for you. The biggest difference between ChatGPT and Gemini is that it is designed with search in mind.
When you type in any question, Perplexity automatically searches the entire Internet and summarizes information from multiple sources. What's more, the source link is displayed with a number in each sentence of the answer, so if you think, "Is this information true?", you can immediately check the original article.
What Perplexity is suitable for
- Breaking news/current events such as "Tell me the latest news about 〇〇"
- Cross-sectional comparison of multiple sites such as “Compare the prices of 〇〇 and △△”
- Summary of official documentation such as "What does the error code 〇〇 mean?"
- Source must be clearly indicatedPreparation of report/proposal
Limitations of the free version (as of March 2026)
Perplexity's Quick Search is free and unlimited. However, there is a limit toPro Search, which searches deeper, up to five times a day, andDeep Research, which creates detailed reports across multiple sources, is limited to five times a day. According to Perplexity official help, if you subscribe to the paid plan (Pro: $20 per month), you can use Pro Search up to 600 times a day and Deep Research up to 500 times a day.
By the way, you cannot choose the AI model in the free version, but in the paid version you can switch to your favorite model such as GPT-4o or Claude 3.5 Sonnet.
ChatGPT is good at "deep digging & writing"
ChatGPT has opened the web search function (ChatGPT search) to all users, including free users, since February 2025. Click the globe mark on the chat screen or enter "/" and select "Search" to enter Internet search mode.
However, the main purpose of ChatGPT is not the search itself, but the ability to dig deep into the collected information and summarize it into easy-to-understand sentences.
What to research that ChatGPT is suitable for
- Understanding and learning concepts such as "Explain 〇〇 in a way that beginners can understand."
- Organizing and structuring information such as "Summary the differences between these three in a table"
- Comparative analysis such as “Please tell me the advantages and disadvantages of 〇〇”
- When you want to write an email or report based on your research
In other words, the most efficient method is to use Perplexity to create a "foundation of facts" and use ChatGPT to finish the "output of sentences and analysis".
Points to note when searching with ChatGPT
ChatGPT's search function is useful, but its weakness is that the source link may not be displayed. When asked, "Tell me about 〇〇," the answer is based on the training data, and in some cases does not reflect the latest information. If you want to make sure that someone searches the internet, either explicitly turn on the globe mark or enter a prompt that says ``Search the web for the latest information.''
Gemini's biggest weapon is "Google collaboration"
Google Gemini's strength is that it is directly connected to Google's search engine. A feature that other AIs do not have is that it can seamlessly integrate with Google services such as Google Maps, YouTube, Gmail, and Google Calendar.
Research topics that Gemini is suitable for
- Local search/map integration Such as “Where can I use electricity at a cafe near me?”
- YouTube search like “Look for the video explaining 〇〇”
- Google Workspace integration Something like "Tell me the details about that thing that's coming to Gmail"
- Image search and generation such as "Show me the image of 〇〇"
Notes on Gemini
Gemini displays links in answers, but they may not be as detailed as Perplexity. Additionally, in February 2026, thought process leak problem was reported, so caution is required when handling highly confidential research materials.
Quick reference table of AI research tools by purpose
| What I want to do | Recommended tools | Reason |
|---|---|---|
| Get the latest news quickly | Perplexity | Summary of the latest information with sources |
| I want to know the exact information on the official website | Perplexity | You can quickly check the original source with the source link |
| Understand specialized concepts in an easy-to-understand manner | ChatGPT | Good at giving detailed explanations and analogies |
| Compile research into a report | ChatGPT | Good at text generation and structuring |
| Find nearby shops and facilities | Gemini | You can also find the location by linking with Google Maps |
| Search the contents of Gmail and Calendar | Gemini | Strong integration with Google services |
| Compare prices for multiple services | Perplexity | Automatically generate comparison table with cross search |
| Programming error resolution | ChatGPT | Excellent code generation and correction suggestions |
Three tips to avoid "weak answers"
No matter which tool you use, the quality of your answers can be greatly improved by thinking about how you ask (prompts).
Tips 1: Tell them “why you are researching”
❌「ChatGPTについて教えて」
✅"I want to create materials to propose ChatGPT implementation to my boss at work. Research three points: cost, security, and implementation examples."
You tell it your purpose and the AI will return you the granular information you need.
Tips 2: Specify "when information"
❌「Perplexityの料金は？」
✅"Please tell me the pricing plan for Perplexity Pro as of March 2026"
In particular, prices and service specifications change frequently, so by clarifying the timing, you can reduce the risk of getting outdated information.
コツ3：回答に出典を求める
❌「〇〇は本当？」
✅"Tell me about 〇〇 with official website and reliable media sources"
Especially in ChatGPT and Gemini, asking for a source makes it easier for the AI to switch to search mode.
FAQ
Is Perplexity completely free to use?
Normal search (Quick Search) can be used for free and without any restrictions. However, the advanced search functions "Pro Search" and "Deep Research" are each limited to 5 times per day (as of March 2026). The free version is sufficient for everyday research.
How do I turn on the search function in ChatGPT?
Click the globe mark (🌐) in the input field on the chat screen to enter "Search the Web" mode. Alternatively, you can enter "/" in the input field and select "Search" from the menu. 無料ユーザーでも利用可能です。
If you were to use only one, which one would you recommend?
If you mainly want to research, Perplexity is recommended. The biggest advantage is that the source is automatically displayed, making it easy to check the reliability of the information. If you also want to create texts, ChatGPT is useful, and if you often use Google services, Gemini is useful.
Is it okay to just believe the AI's answer?
With any AI tool, the risk of "hallucination" (plausible lies) is not zero. In particular, be sure to check the official website or primary source before using any information related to numbers, fees, or laws.
References
- Getting Started with Perplexity — Perplexity AI Official Help
- ChatGPT search — OpenAI Help Center (Japanese)
- Collect information with "ChatGPT", "Gemini", and "Perplexity". Summary of Deep Research usage examples and differences between companies — Business Insider Japan
- What is Perplexity AI? Explaining the differences and points to note with ChatGPT — mouse LABO, February 2026
