ChatGPT vs Gemini vs Copilot vs Perplexity vs DeepSeek (2026)

Where the five AIs are now

Our 2025 article compared ChatGPT, Copilot, Perplexity, DeepSeek and Gemini. As of October 2026, all five are still running. But the AI models inside them, and the way you use them, have changed a lot since then.

Here are the main changes of the past year or so, service by service.

ChatGPT, Gemini and DeepSeek all released a new generation of models in 2026. Copilot changed the shape of its app, and Perplexity changed how it combines models. The "five AIs" we compared in March 2025 have the same names, but it is more accurate to treat them as different products now.

HIKARI'S TAKEAll five are still around, but what's inside has changed a lot. Please don't assume the "personalities" measured in 2025 still fit them today.

Checking our 2025 article

Our March 2025 article compared the five AI chatbots using DISC, a model that sorts human behavior into four styles: D for Dominance, I for Influence, S for Steadiness and C for Conscientiousness.

It was based on an article by Online DISC Profile, a company that sells DISC assessments. That article placed the five AIs in these types.

We read the original article again. It does not say when the assessment was done, on which models, or by what method. We also cannot tell how many times it was run. The original article itself advises against using AI output as is and says to always edit it. With that in mind, here is how what we wrote then compares with today.

There is one more thing we did not see at the time: an AI's tone changes when its maker updates it. In April 2025, right after updating GPT-4o in ChatGPT, OpenAI rolled the update back because responses had become overly agreeable with users. OpenAI said the cause was giving too much weight to short-term user feedback. It also said it was testing ways to let users choose from several "personalities".

Our biggest miss was treating the assessment as a reason to choose an AI without checking where it came from or how it was done.

HIKARI'S TAKEWe reported the source correctly. But it was a one-off result with an unknown method, and an AI's tone can change with any update. Looking back, it was too weak to choose an AI by.

What each of the five AI chatbots is like in 2026

Now we compare the five as they are today. Instead of personality types, we use what each company has announced. In the table, the middle column is what official announcements and press reports confirm, and the right column is how we think each one could be used. Please read the two separately.

What the table shows is that what separates the five today is less their "personality" and more where they run and what they connect to. Gemini is built into Google's services, and Copilot into Microsoft 365. Perplexity's defining feature is that it doesn't depend on any one model. In February 2026, a Perplexity executive told TechCrunch that "multi-model is the future."

Seen that way, it is more practical today to choose by which tools you already work in and what information you are allowed to give an AI, rather than by which AI seems outgoing.

HIKARI'S TAKEThe real differences now show up in which work tools each AI connects to, more than in personality. Start from the email and document tools you already use, and the choice gets easier.

You can set an AI's personality: ChatGPT and Gemini

Our 2025 article said you could change an AI's personality to some degree with prompts like "please be gentler." Things have gone further since: some services now let you choose a tone in the settings.

ChatGPT added eight base styles in November 2025, with the release of GPT-5.1: Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy and Cynical. You choose one in settings and can change or undo it at any time. In December 2025, personalization settings also gained controls for warmth, enthusiasm, the amount of headers and lists, and the amount of emoji, each set to more, default or less.

Gemini announced "skills" on September 30, 2026. A skill saves instructions you use often, and you call it by typing "/" in the prompt box. Existing Gems will start moving to skills automatically on November 17, 2026. On October 13, Gemini also added a "Customize" menu for setting how it responds.

For Copilot, Perplexity and DeepSeek, we found no similar announcement of a feature for choosing tone. With these, putting your instructions at the start of the conversation still works.

If you set a work tone in this order, you won't get lost.

1. Write your rules for outside-facing text in three lines. For example: "Use a professional tone," "Lead with the conclusion," "No emoji."
2. Save them in AIs that have settings. In ChatGPT, use the base style and fine-tuning controls. In Gemini, use Customize or a skill.
3. Paste them at the start of the chat in AIs that don't. Keep the text in a note so you can reuse it every time.
4. Give the same request to two AIs and compare. Whichever needed less editing gets that job.

HIKARI'S TAKEAn AI's tone has gone from something you pick to something you set. If you write your company's style rules in three lines, you can bring any AI close to the same voice.

Plans for the five AI chatbots, and what to check before using them at work

All five can be started for free. Paid plans change which models you get and how much you can use them. Prices change often, so check the official pages before you sign up.

US prices for Google AI Plus and Pro are from Google's US plans page (checked October 26, 2026); Engadget (June 2026) reported the AI Plus price cut. ChatGPT prices are from Android Authority (January 2026) and OpenAI's help center (Pro tiers, checked October 26, 2026). Perplexity Max is from TechCrunch (February 2026).

More important than price are the four points below. They apply to all five if you use AI-generated text or images in your work.

1. Check rights. Under general U.S. copyright principles, output that copies protected expression from an existing work can infringe, no matter what tool produced it. The U.S. Copyright Office also concluded in January 2025 that AI output is protected only where a human has determined sufficient expressive elements, and that prompts alone are not enough. Before publishing text or images, check that they don't resemble existing work, and don't assume you own them outright.
2. Don't publish it as is. Have a person check facts, numbers and names against the original sources.
3. Decide what goes in. Before entering customer data or confidential information, find out where the service stores data and how it handles it. DeepSeek's privacy policy says it stores the data it collects on servers in China.
4. Keep what you make. In the consumer Copilot app, group chat content was wiped in August 2026 and podcasts could no longer be viewed. Save important conversations and outputs to your company drive.

HIKARI'S TAKEYou can try every one of these for free. Before you think about price, decide what information may go in and what gets checked before it goes out. And don't leave what you make sitting inside the service.

What to decide before personality: choosing an AI chatbot for a small company

Over the past year, all five AI chatbots changed a lot inside, and Copilot even changed the shape of its app. Six months from now they may look different again. So we have stopped choosing AIs by personality, and decide in this order instead.

1. Start from the tools you already use. If your work centers on Gmail and Google Docs, try Gemini. If it centers on Word and Outlook, try Copilot. If neither, start with ChatGPT.
2. Pick one main AI and one for checking. Ask a second AI about important answers and compare. Where they disagree is where a person needs to look.
3. Write down what information may go in, first. Decide how to handle personal data, client information and unreleased figures before you start.
4. Set the tone in settings. Put your company's style rules into the settings or a standing instruction.
5. Review every six months. Check models, prices and discontinued features, and update how you use them.

Our 2025 article was useful as a prompt to notice that AIs differ. But we now think an AI's character isn't something you measure once. It's something you shape to fit how your company works.

HIKARI'S TAKEAIs change quickly, so a fixed order for choosing lasts longer than memorizing personalities. Start today with one AI that sits close to the tools you already use.