What Is Claude? A Beginner’s Guide to How It Differs from ChatGPT and How to Use It

Intro

Lately, you’ve probably been hearing the name “Claude” a lot, right?
I bet a lot of you have played around with ChatGPT but have only heard of Claude by name.

I used to think “ChatGPT is plenty, why bother” myself.
But before I knew it, I now use both ChatGPT and Claude heavily, each for different things.

The reason is simple: they’re good at completely different things.
Stuff I got stuck on in ChatGPT gets solved instantly in Claude, and vice versa.

In this post, for anyone who’s serious about actually using AI, I’ll walk you through the basics of Claude, how to get started, and how it differs from ChatGPT, keeping the jargon to a minimum.
By the time you finish reading, you’ll be thinking “okay, let me just give Claude a try.”

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What is Claude? ChatGPT’s rival, built by an AI company called Anthropic

To explain Claude in one line: it’s a conversational AI built by an American company called Anthropic.

ChatGPT is OpenAI, Gemini is Google, and Claude is Anthropic.
If you remember the AI industry with this kind of map in your head, then whenever you see the news you’ll go “ah, that company.”

It’s pronounced “Clawed”

It’s pronounced “Clawed.”
It sounds like a French name, but it actually comes from Claude Shannon, an American mathematician. The name is taken from the man known as the father of information theory.

Built by Anthropic, founded by former OpenAI members

Anthropic was founded by Dario Amodei and Daniela Amodei, a brother and sister who originally held senior positions at OpenAI.
They broke away with the philosophy of “we want to build AI more safely” and launched the company in 2021.

In other words, it’s an AI built by top talent out of OpenAI, with safety as the number one priority. That’s Claude.

3 reasons Claude is getting so much attention

First, its writing is overwhelmingly natural.
It’s especially praised for its Japanese, and you often hear people say “it writes more human-sounding text than ChatGPT.”

Second, it can process long documents all at once.
You can feed it a document on the scale of a million characters and it’ll understand and answer based on the content. Summarizing a book’s worth of meeting notes is no problem at all.

Third, its coding ability is top-tier.
It often beats ChatGPT on programming benchmarks, and more and more engineers are switching over.

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Comparing Claude and ChatGPT across 5 angles

“So in the end, what actually makes it different from ChatGPT?”
I think this is what most people are dying to know. Let’s go through them one by one.

Difference 1: Claude wins by a mile on long-document handling

Claude can read in around a million characters (two million tokens) at once.
For example, you can paste in an entire 150-page PDF and ask “just give me the key points as bullet points,” and it does it in one shot.

ChatGPT handles long text too, but it doesn’t yet have the same level of stability as Claude.
If you want AI to read contracts, meeting notes, papers, or long articles, Claude is the only choice.

Difference 2: Claude also has the edge on natural Japanese

This varies from person to person, but Claude’s Japanese has less of that “translated” smell.
Text generated by ChatGPT tends to scream “an AI clearly wrote this,” whereas Claude tends to land at around the level of “a rough draft a human wrote.”

For text meant to be read by people, like blog posts, emails, or LINE replies, Claude is the better fit.

Difference 3: Only ChatGPT does image generation

This one’s crystal clear.
Claude can’t generate images.
It can read images (look at a photo and describe it), but actually drawing pictures is ChatGPT’s (DALL-E’s) specialty.

If your goal is to make a header image for a note article or create an SNS icon, use ChatGPT.

Difference 4: The pricing plans differ

Both let you try them for free, so that part’s the same.
The paid plans break down roughly like this (as of May 2026).

ChatGPT Plus: around $20/month
Claude Pro: around $20/month
Claude Max: $100 to $200/month (for heavy users)

The pricing is pretty much the same.
That said, Claude lets you use a terminal version called Claude Code within the paid plan, so for engineers and efficiency junkies, Claude feels like the better deal.

Difference 5: The bottom line, here’s the right way to split them up

If someone told me “pick just one,” the right answer is to split them by use case.

For writing, long-document processing, and coding, go with Claude.
For image generation or casual chatting, go with ChatGPT.
If you want it to connect with Google services like Gmail or Google Drive, go with Gemini.

In my case, I use ChatGPT for image generation, Gemini for Google integration, and Claude Code for code, automation, and tool building, completely splitting them up by role.

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7 things you can do with Claude

Let me introduce 7 of the things I use it for most, so you get a concrete idea of what it can do.

1. Summarizing and comprehending long documents

You can upload anything: PDF, Word, plain text.
Just ask “give me 3 key points from this document” or “pull out only the important numbers,” and you can fully hand it off and get an answer back.

2. Writing and drafting blog posts

It can write anything: blog posts, emails, proposals, SNS posts.
The key is not to “dump everything on it,” but to ask it to “write a draft” and then finish it yourself.
That way you keep your own voice while cutting down only the time.

3. Programming and fixing code

Just paste in the code that’s throwing an error and say “fix it.”
We’ve reached an era where even people with zero programming experience can build a little automation script.

4. Reading and explaining images

You can show it a photo or image and ask things like “what’s in this?” or “this floor plan, roughly how many tatami mats is it?”

5. Data analysis and calculation

You can hand it a CSV file and have it do things like “give me the average” or “show it to me as a graph.”
The worse you are at Excel, the bigger the payoff.

6. Translation

Translation accuracy on par with DeepL.
English emails, overseas papers, articles on English sites, it can translate anything.

7. Brainstorming and a sounding board

This one’s surprisingly handy.
If you ask “I’m thinking about this plan, poke holes in it,” it’ll go after the weak spots more bluntly than a human would.

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How to get started with Claude (you can try it free right now)

Let me walk you through the “okay, so how do I actually get started?” part.

Go to claude.ai and sign up

Head to the official site, claude.ai.
Just sign up with a Google account or an email address. It takes one minute.

What you can and can’t do on the free plan

Even on the free plan, you can use writing and summarizing just fine.
However, there’s a cap on how many messages you can send per day, so if you use it hard you’ll burn through your quota quickly.

When do you need a paid plan (Pro/Max)?

If any of the following apply to you, it’s fine to consider paying for Pro.

People who use Claude dozens of times a day
People who frequently feed it long documents
People who want to use the latest, strongest model (Claude Opus)
People who want to use it seriously for work

For $20 a month (about 3,000 yen) it gets comfortable on a whole different level.

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What is “Claude Code,” the way to use Claude even deeper

Once you get a little used to Claude, the next wall you hit is “I want to automate more” and “I want to leave even file operations to the AI.”

That’s where Claude Code comes in.

An expanded version of Claude that runs in the terminal

If the browser-based claude.ai is “Claude the conversation partner,” then Claude Code is “Claude that does work on your computer.”

It reads files, rewrites them, saves them, and runs commands.
And it does all of this just from instructions you give in plain language.

3 reasons the whole landscape of your work changes

First, you can hand even file operations off to the AI.
“Summarize all the meeting notes in this folder and save them to an md file” finishes in a single command.

Second, you can combine multiple AIs (agents).
You can even run setups where you link up a research AI, a writing AI, and a proofreading AI to mass-produce blog posts in one go.

Third, the entire work log is kept.
Because you can see what the AI did, reviewing and fixing is easy. Rolling things back is reassuring too.

The clincher that made me start splitting them up

One day, I needed to pull just the key points out of 30 sets of meeting notes and compile them into a CSV.
By hand, that’s a solid two-day job.

I asked Claude Code to “read the meeting-notes folder and compile just the project name, decisions, and action items into a CSV,” and it was done in 15 minutes.

At that moment I was convinced “this is going to change the whole landscape of my work,” and ever since, I’ve used them completely split up by role.

I still use claude.ai for long-form brainstorming and summarizing, but the one that really starts paying off for serious work was Claude Code.

ChatGPT: image generation
Gemini: Google integration (Gmail, Drive, Calendar)
Claude Code: automation, code, tool building

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1 mistake beginners tend to make

It’s the trap of “trying to leave everything to the AI.”

AI isn’t all-powerful, and it makes mistakes.
It’ll cheerfully get the latest info, proper nouns, and numbers wrong, so always have a human do the final check.

Not “leave it all to the AI,” but “have the AI write a draft and a human finishes it.”
This is the right answer that’s both the easiest and gives you higher quality.

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For those who want to master it even more

For anyone who read this far and thought “I want to master Claude Code more.”

On this blog I covered the entry point from beginner to intermediate, but I’m planning to go one step deeper into “how to design a project to really master Claude Code,” coming soon as a paid post on note (¥500).

Here’s what’s planned to be included.

The 3 MD files you should create before starting a project (with the actual files shared)
The hands-on flow for driving Claude with a spec-first approach
The 7 experiments I tried with Claude that actually worked
The pitfalls intermediate users often fall into, and how to avoid them
A roadmap for people who are going to use Claude seriously from here on

I’ll pack in only the deeper know-how that won’t fit on the blog.

▶ Please go ahead and follow my note “Pon’s Hobby Room” (in Japanese). You’ll get a notification when it goes live.

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For those who want to learn AI more systematically

The intermediate note edition goes all-in on “project design and practical operation,” but I figure some of you want to understand AI as a whole from the ground up first.

For those people, let me introduce just one book and one course.

If you’re going to read one book first, this is it

“How Generative AI Will Change the World” by Shota Imai (SB Shinsho)

A book that gives you a bird’s-eye view of how generative AI will change society, the way we work, and the way we learn.
Rather than surface-level arguments like “AI is going to take our jobs,” it calmly lays out what’s going to happen from here and how we should prepare.

The reason I recommend this book is simple: if you get a flat, level grasp of “what AI is” once before touching Claude, your speed at choosing tools and learning afterward completely changes.

It’s shinsho-sized, so you can finish it in two hours. As your very first book for learning AI, there’s no better choice.

By the way, this book is also available on Audible (4 hours 28 minutes / ¥1,300). Just play it through your ears during your commute, chores, or workout, and you’ll finish a book in 2 to 3 days. Audible is free for the first 30 days, so it’s incredibly cost-effective as an entry point into learning AI.

▶ Listen to “How Generative AI Will Change the World” on Audible (30-day free trial)

If you want to learn thoroughly through video, an online course

For people who aren’t great at reading books, or who want to learn by getting their hands moving, an online course is the better fit.

What I especially recommend is a specialized school focused on generative AI, whose strength is systematically covering everything from beginner to professional level.
Even just the free counseling session helps you sort out what level you’re at right now and how you should learn, so there’s value in simply hearing them out first.

▶ No environment setup needed! Hands-on AI agent development even for non-engineers [AI Agent Camp]

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Frequently Asked Questions (FAQ)

Does Claude support Japanese?

It fully supports it.
Lots of people say its Japanese is more natural than ChatGPT’s.
The interface can be displayed in Japanese too.

Is Claude safe? What about data leaks?

Anthropic is a company specialized in AI safety, and on paid plans, the content you input is set up so it isn’t used to train the AI.
That said, if you’re going to input a company’s confidential information, be sure to check your internal rules first.

How much is Claude’s free quota?

It’s limited by message count.
From my experience, around 20 to 30 messages a day.
The longer the messages you send, the faster you burn through it.
If you’re going to use it heavily, I strongly recommend paying.

Is Claude Code included in Claude Pro?

It’s included.
If you’re paying for Claude Pro, you also get a certain quota of Claude Code.
The Claude Max plan gives you an even bigger quota.

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Wrap-up: start by just trying the free claude.ai

This got long, so let me wrap it up at the end.

Claude is a rival AI to ChatGPT, built by Anthropic
It’s especially strong at long-document processing, Japanese expression, and coding
Only image generation is ChatGPT’s specialty, so splitting them up is the right move
To get started, just sign up at claude.ai. You can try it for free
If you want to go one step further, there’s Claude Code. The whole landscape of your work changes

If you’re interested in AI, just open up claude.ai for now and throw it whatever question you like.
You’ll notice “huh, isn’t this reply more natural than ChatGPT’s?”

And if you want to seriously bring Claude into your work, give Claude Code a try.
From there on, it’s literally a whole different world.

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[Follow my note too if you’d like]
I post AI × hobbies × slightly deeper talk twice a week on my note “Pon’s Hobby Room.”
There are also paid articles I can’t write on the blog.

▶ https://note.com/oidon_lucky_777

Pon