You don't need to install ChatGPT, Gemini, and Copilot all for free—the criteria for choosing is 'where you spend your time'

ChatGPT, Gemini, Copilot. You hear the names, but without knowing the differences, you end up installing them all and using each one half-heartedly—I think this is quite common. Let me give you my conclusion first.

You don't need to have all of them for free. You just need to decide on one. The way to choose that one is simple: just lean toward the place where you spend the most time.

Why is that? Although these three share the same name, 'AI chat,' their personalities are clearly different. Today, I will talk deeply about just that. I won't make a detailed comparison table of usage limits (in the first place, I can't make one anymore. I'll talk about this in the second half).

The three have different 'personalities.' First, they can be divided into two groups based on their underlying technology.

First, I will give you the most useful perspective. Instead of lining the three up side-by-side, if you divide them into two groups based on their 'underlying engine lineage', it will all make sense at once.

ChatGPT is genuine OpenAI.

Copilot runs by borrowing that OpenAI engine (GPT series) (DX/AI Research Institute — What you can do with the free version of Copilot).

In other words, ChatGPT and Copilot are close relatives with very similar internals. On the other hand, only Gemini is a genuine Google engine, and its lineage is completely different. Once you grasp this, you can see how 'trying all three for no reason' is such a roundabout way of doing things.

There is little to gain from holding onto both of the two with similar internals.

With that in mind, here is a word for each of the three personalities. ChatGPT is the 'universal benchmark.' It has a good balance of natural Japanese and versatility, and there are tons of explanations on the internet on how to use it.

There is a sense of security in knowing you can return here if you get stuck (aismiley — Limitations of the free version of ChatGPT). Gemini is the 'research assistant.'

It is closely integrated with Google Search, Gmail, and Docs, and even in the free version, it connects to peripheral 'research' features like image generation and Deep Research (investigative reports) (AI PICKS — Summary of limitations for the free version of Gemini).

Copilot is the 'built-in Windows assistant.'

It is pre-installed on Windows, requires zero setup, and is strong at the latest Bing searches and summarizing PDF/Word Office files (Digital Growth Academia — What you can do with the free version of Copilot).

Having different personalities means exactly this. It's not about superiority or inferiority; it's that they live in different places.

So, which one should I use?—Choosing based on 'where you usually are' eliminates hesitation.

Rather than looking at a quick reference table, it's faster to think about your daily life for a second. Which app do you have open the most on weekdays?

If you don't have a particular preference and just want to decide on one, then honestly, it's ChatGPT. Being a universal benchmark is no joke; it's hard to go wrong as your first choice. Even if you get stuck on how to use it, you will always find answers from others if you search. If you start here and feel dissatisfied, you can think about switching then.

If your day revolves around Gmail and Google Docs, you can just start with Gemini. Drafting emails, summarizing documents, doing quick research—if your data and work are already inside Google, using the AI that lives there is the easiest way.

The number of free image generations is also relatively high among the three, so it's convenient when you want a quick image (AI PICKS (same as above)).

However, if you are serious about image generation itself, I will leave that to a separate article (mentioned later).

If your work is centered on Windows and Office, use Copilot primarily. There is no reason not to use what is already installed. Let me be honest here and talk about the pros and cons. I said that ChatGPT and Copilot are close relatives in terms of content.

That is why there is little point for someone who works on Windows to install both ChatGPT and Copilot. Something essentially close to ChatGPT is already installed on your PC.

Try to see if Copilot is enough first, and if it's not, add ChatGPT—this order will keep your mind clearer.

Honestly, there are almost no free chats where I can post affiliate links here (the three major companies hardly offer referral rewards for individuals). That is precisely why I can say this without hesitation: It is a waste to be satisfied with installing all three. You will definitely get better at it if you master just one.

However, there is one pitfall with the free version of Copilot regarding work, which I will touch upon next.

'How many times can I use it for free?' can no longer be answered with a fixed number

This is the newest information for today. Until recently, articles of this type were filled with numbers like 'free usage is limited to X times per day.' If you take those numbers at face value now, you will likely be wrong.

Entering 2026, both ChatGPT and Gemini are moving away from fixed 'X times per day' limits toward a variable system of 'reset every 5 hours + weekly limits' (AI Research Institute — Gemini usage limits / ChatGPT Summary — Models available in the free plan).

Moreover, each company is becoming less clear about publishing fixed numbers. In the case of ChatGPT, for example, the only 'guideline' provided is that high-performance models are roughly 10 messages per 5 hours, and it will automatically switch to a lighter model if you exceed that.

Therefore, the correct way to interact with them is this: Stop trying to memorize the exact number of times and just look at the remaining display on the screen. If you hit the limit, you will either drop to a lighter model or it will return after a few hours. If you know just that, daily use will be more than enough even for free.

It is much faster to actually try it out and see if it meets your needs than to spend time on articles chasing numbers.

And one more thing to keep in the back of your mind as a trend is that the free tier is generally 'shrinking'.

In Japan, ChatGPT also started showing ads in its free/introductory plan from June 2026 (Impress Watch — ChatGPT starts displaying ads in Japan.

I wrote about this ad situation in detail in my previous article 'Complete Guide to Free AI Tools', so I will leave it as an 'example of the cost' here).

Copilot also had a change starting in April 2026 where users without a license in large organizations (2,000 seats or more) can no longer use Copilot within Office apps (AI Research Institute — Copilot Chat free usage to be restricted).

This is a story for people using it at work, and it is a different layer from the individual free web version, but the atmosphere that 'the range of things you can use for free is narrowing rather than expanding' is real.

By the way, here is one weak point of the free version of Copilot: The free version cannot run AI directly 'inside' Word, Excel, or PowerPoint. It requires the extra step of creating it in a browser and then copying and pasting.

If you want to use it directly within an app, a paid subscription (from 3,148 yen/month) is required (DX/AI Research Institute (ibid.)).

It is true that it is 'strong with Office,' but if you keep in mind that the free battlefield is limited to 'document summarization and drafting,' your expectations won't be off.

Stick to one, or use them selectively—my answer

Conclusion.For most people, one is enough. First, master the one that fits the 'place where you usually spend your time' chosen above. Rather than half-heartedly touching all three, knowing one deeply will definitely make your work faster.

I only recommend using them selectively when combining two with different personalities. For example, if you divide them by role, such as 'ChatGPT for daily writing, Gemini for thorough research,' it makes sense to use two with different characteristics.

Conversely, I don't really recommend using both ChatGPT and Copilot, which are similar in nature. Having two similar tools won't increase your options.

Furthermore, for those who want to do image generation 'seriously,' don't waste your time with the bonus features of a chatbot.

Free image generation AIs, including the 'pitfalls of commercial use,' are summarized in another article, so it's faster to read that.

The free tiers and usage limits are in a world that changes quietly by next month. At this institute, I plan to next verify 'whether it is really enough to actually run a week's worth of work using only the big three free tools,' from the perspective of usability rather than numbers. If you are curious about the results, please follow and wait.

If you think it might be useful, I'd be happy if you came back to take a look.