Short answer
ChatGPT, Claude and Gemini all have a website and a phone app, and you can sign up and start for free. After signing in, type your question in the box at the bottom and send it. To add a photo or document, use the add button next to the box (usually a plus sign). Menu names and free limits change often, so this guide sticks to the steps the three services share.
Step 1. Where to start
All three work on the web and as a phone app. On a computer, open the website in a browser. On a phone, install the app.
- Check that the developer name in the app store is the real company. Copycat apps with similar names exist.
- Claude's help page says you must be 18 or older and in a supported location. The other services have age and region rules too, so read the terms on the sign-up screen.
ChatGPT (OpenAI)
- Website
- chatgpt.com
- Phone app
- iOS, Android
Claude (Anthropic)
- Website
- claude.ai
- Phone app
- iOS, Android (desktop apps for Mac and Windows too)
Gemini (Google)
- Website
- gemini.google.com
- Phone app
- Gemini app (search your app store)
Step 2. Sign up for free
Sign-up differs a little by service. You usually create an account with an email address or an existing account such as Google. For Gemini, you sign in with a Google account. You can normally start free without adding a card. If a screen pushes a paid plan, you can skip it.
Free use has limits. Claude's help page, for example, says the free plan has a session-based usage limit that resets every five hours. When you reach a limit the service tells you, and you can use it again later. Exact limits can change.
Use a personal account for personal things. If you want to use AI for your job, check first that your employer allows that service.
Step 3. Send your first question
Type what you want in the box at the bottom, in everyday language, then press the send button or Enter. A full sentence that says what you want works better than a few keywords.
This is my first time using AI. I live with a cat. Give me 5 simple play ideas I can try this weekend. Only use things I probably already have at home.
If the answer is long, follow up with "shorten that to three lines".
Step 4. Upload photos and documents
Use the plus or paperclip button near the message box. In Claude, per its help page, you click the "+" at the lower left of the chat box and choose "Add files or photos". In the Gemini web app, you click the add files icon in the prompt box. GPT also has an add button in the message box. The icon can look different depending on your screen or app version.
After uploading, say what you want done with the file. If you send only the file, the AI does not know what the task is.
- According to Claude's help page, you can upload documents such as PDF, DOCX, CSV and TXT, and JPEG, PNG, GIF and WebP images, up to 20 files per chat.
- According to Gemini's help page, you can attach up to 10 files to one prompt, and most file types can be up to 100 MB each.
- Limits vary by service and plan and can change. If an upload fails, try splitting or shrinking the file.
- Do not upload files with ID numbers, bank details or confidential work material.
This photo is the back of my cat's food bag. Read the ingredient list and explain in plain words what the first five ingredients are. Do not make any medical judgments.
Step 5. Keep going, or start a new chat
- Follow up: in the same chat you can say "turn that into a table" and it remembers what came before. If you do not like the answer, ask for changes: "shorter", "more formal", "for a ten-year-old".
- New chat: when the topic changes completely, start a new chat. Old context can mix in and make answers odd. Look for the "New chat" button on screen.
- Find old chats: past conversations are listed in the side menu (on a phone, behind the menu icon).
- In a very long chat, the AI can lose track of the early part. Repeat important conditions.
Using the phone app
If you sign in with the same account, your chats usually carry over between web and app. The app makes it easy to upload a photo straight from the camera or to talk instead of type. A simple way to start is to photograph a receipt, a notice or a foreign-language menu and ask: "Summarize this and translate it into English."
Voice and camera features differ by service and plan. Check the app's settings or help pages.
Related terms
- Chat
- One conversation with the AI. Opening a new chat starts a separate one.
- Free plan limit
- The cap on how much you can use for free. Read the message the service shows you.
FAQ
Do I need to write in a specific language?
No. All three services handle many languages. Write in the language you are most comfortable with.
Can I sign up for more than one service?
Yes. You can ask the same question in two places and compare. Check each service's terms and privacy settings separately.
Can other people see my questions?
By default, no. But if you create a share link for a chat, anyone with the link can see it, so check the content before sharing.
What if the answers seem off?
Rewrite the question with more detail, or start a new chat. Check anything factual on an official site.
Keep going
Checked against sources on 2026-11-05. Sources: Claude Help: Uploading files, Claude Help: Creating a Claude account and usage limits, Gemini Apps Help: Upload files. How we write