How to Use ChatGPT on iPhone: App, Siri, Action Button and More

How to use ChatGPT on iPhone: download the free ChatGPT app from OpenAI in the App Store, sign in, and start typing or talking. The app needs iOS 18 or later. On an iPhone 15 Pro or any iPhone 16 or later, you can also turn on ChatGPT inside Siri, which on iOS 27 sits under Settings, then Siri, then ChatGPT.

Most guides to this still describe iOS 18 menus, the Bing app or a Shortcut that needs an API key. This one covers what works in October 2026. That means the app, Siri, Writing Tools, the camera, the Action Button and the Lock Screen, plus three ways to reach ChatGPT with no app at all. Each method comes with the iPhone it needs, because that is where most setups fail. It also flags one place where the popular advice is out of date: ChatGPT on WhatsApp, which OpenAI has brought back in Europe.

The Key Takeaways

• The app: ChatGPT is free in the App Store and needs iOS 18.0 or later. Plus costs $19.99 a month as an in-app purchase.
• Siri: on iOS 27, go to Settings, then Siri, then ChatGPT. It needs an iPhone 15 Pro, 15 Pro Max or iPhone 16 or later, and works without a ChatGPT account.
• One press to talk: on an iPhone 15 Pro or later, the Action Button can open ChatGPT Voice directly.
• Free plan: unlimited text chats with GPT-6, with limited voice, images and uploads. Voice with video needs Go or higher.
• No app needed: chatgpt.com in Safari, 1-800-CHATGPT calls (30 free minutes a month in the US and Canada), and WhatsApp in the EEA.

How to Use ChatGPT on iPhone: Which Method Fits Your Phone

The right way to use ChatGPT on iPhone depends on your model. The ChatGPT app runs on any iPhone that can install iOS 18. The Siri, Writing Tools and Visual Intelligence routes need Apple Intelligence, which Apple limits to the iPhone 15 Pro, iPhone 15 Pro Max and every iPhone 16 or later. The table shows every route side by side.

To check your iOS version, open Settings, then General, then About. If your iPhone cannot install iOS 18, the browser, the phone line and Fello AI are the routes left.

How to Use the ChatGPT App on iPhone

The ChatGPT app is the best way to use ChatGPT on iPhone for most people. It is the only route with every feature: voice, the camera, image generation, file uploads and your full chat history. It is free, it is published by OpenAI OpCo, LLC, and the App Store lists it as needing iOS 18.0 or later.

Install and Sign In

1. Open the App Store and search for ChatGPT.
2. Check that the developer is OpenAI OpCo, LLC, so you install the official app and not a third-party client.
3. Tap Get and install the app.
4. Open it and sign in with Apple, Google, Microsoft or an email address. Use the same method as your existing account, or your old chats will not appear.
5. Type in the message box at the bottom, or tap the voice icon to talk.

Your chats sync with chatgpt.com and the ChatGPT apps on other devices, so a conversation started on iPhone continues on a Mac or a PC. For a direct link, the official listing is ChatGPT on the App Store.

Talk to ChatGPT With Voice

ChatGPT Voice on iPhone runs on GPT-Live-1.1 on Plus and Pro, and on the smaller GPT-Live-1.1 Quip on Free and Go, according to OpenAI's Voice help page. Both replaced the GPT-Live-1 models on 15 October 2026. Go moved to the mini model on 9 September 2026, with up to 3 hours of voice a day, the same daily cap as Plus. Both models listen and speak at the same time, so you can interrupt mid-answer. Spoken replies appear as text in the same chat, which means you can switch between typing and talking without losing the thread.

A voice chat can keep running after you leave the app. Turn on Background conversations in the app's Settings, under Voice, and the conversation shows on the Lock Screen and in the Dynamic Island while you use other apps. Voice with video, where ChatGPT sees your camera feed while you talk, is not on the Free plan. Our guide to ChatGPT voice mode covers the voice settings in more depth.

Use the Camera, Photos and Documents

The ChatGPT app reads anything you photograph or upload. Take a photo inside the app, pick one from your library, or attach a file. A photo of a handwritten recipe becomes typed text; a photo of a landmark gets an explanation.

For paper documents, OpenAI's release notes list a Scan mode in the camera, added on 1 October 2026 and rolling out on iOS. Open the camera in ChatGPT, tap the three-dot menu, and choose Scan. You can capture several pages in a row, and ChatGPT combines them into one PDF before uploading it to your chat. Audio file uploads, added on 6 October 2026, are for paid plans only.

Free vs Paid ChatGPT on iPhone

ChatGPT's Free plan on iPhone gives you unlimited text chats with GPT-6, subject to OpenAI's abuse guardrails, plus limited uploads, image creation, voice chats and deep research. In OpenAI's plan table, the Free and Go plans run GPT-6 Luna, while Plus and Pro add the Sol models.

Paid plans bought inside the app are billed by Apple. On the App Store, Go costs $8.00 a month, Plus $19.99, and the main Pro tiers $100 and $200. The listing also shows a $500 Pro tier and credit packs. One catch: OpenAI's help center says that to go straight from Free to Pro, you must upgrade on the web. OpenAI also notes that the Go plan "may include ads". Our breakdown of what ChatGPT's Free plan includes lists the limits plan by plan.

How to Use ChatGPT With Siri on iPhone

ChatGPT works inside Siri on any iPhone with Apple Intelligence: the iPhone 15 Pro, iPhone 15 Pro Max, and every iPhone 16 model or later. You do not need the ChatGPT app or a ChatGPT account. On iOS 27, Apple moved the setting, and most guides still point to the old menu.

Turn On ChatGPT in Siri

On iOS 27, the ChatGPT switch sits under Siri in Settings.

1. Open the Settings app.
2. Tap Siri.
3. Tap ChatGPT, then tap Set Up.
4. Follow the onscreen steps and choose whether to sign in with a ChatGPT account.

If you have joined the Siri AI beta, the steps differ: tap Set Up Extensions, tap ChatGPT, then turn on Use Extension. Apple says Siri AI is not initially available on iOS in the EU.

Signing in is optional. Apple's documentation says your requests are saved to your ChatGPT history only if you are signed in. Older versions of iOS put the same switch under Apple Intelligence & Siri, so if a guide sends you there, look under Siri instead. The full setup is in Apple's guide to turning on ChatGPT.

Ask Siri to Use ChatGPT

Once the ChatGPT extension is on, start a request with "ask ChatGPT". One of Apple's own examples is "Hey Siri, ask ChatGPT to compose a haiku about dragons". Another is "Hey Siri, ask ChatGPT to summarize this document for me", said with a PDF open in the Files app. Siri can also pass along what is on screen, such as a photo of fruit open in Photos with the question "what kind of recipes can I make with this?"

By default, iPhone asks you to confirm before any of your information goes to ChatGPT.

To skip that prompt, open Settings, tap Siri, tap ChatGPT below Extensions, and turn off Confirm Requests. Apple notes that this option is not available if you use the Siri AI beta.

What Apple Sends to ChatGPT

Apple says the ChatGPT extension sends your request, any attachments, and limited data such as time zone, country, device type and language. Your IP address is hidden from OpenAI, but your general location is shared. Without a ChatGPT account, OpenAI must not store your requests or use them to train its models. Once you sign in, your ChatGPT account settings and OpenAI's own privacy policies apply instead.

Why ChatGPT Is Missing From Siri Settings

ChatGPT is missing from Siri settings for one of four reasons. Your iPhone is older than an iPhone 15 Pro. Apple Intelligence is off, or not offered in your language or region. The ChatGPT service is not available in your country. Or Screen Time blocks it, which parents can set. Apple also requires users to be at least 13. Our guide to which iPhones support Apple Intelligence settles the device question, and the walkthrough on replacing Siri with ChatGPT covers what Siri can and cannot hand over.

Use ChatGPT in Writing Tools and Visual Intelligence

The ChatGPT extension also works outside Siri, in two Apple Intelligence features. Writing Tools writes text for you in almost any app. Visual Intelligence answers questions about what your camera sees. Both need the same iPhone 15 Pro or later and the ChatGPT extension turned on.

Compose Text With ChatGPT

To have ChatGPT write a message, email or note for you, tap any text field, tap the Writing Tools button, swipe up, and tap Compose. Describe what you want, choose whether ChatGPT should use all the text or only your selection, and send it. You can then rewrite the result, keep ChatGPT's suggestions, or revert to your original text.

Ask ChatGPT About What the Camera Sees

Visual Intelligence sends a camera view to ChatGPT and lets you ask follow-up questions. Open it, point your iPhone at an object, and tap the ChatGPT button. You can type or dictate a follow-up question at the bottom of the screen.

There are four main ways to open Visual Intelligence. On an iPhone with a Camera Control, click and hold it. Apple lists the Camera Control on the iPhone 16, 16 Plus, 16 Pro and 16 Pro Max, the iPhone 17, 17 Pro and 17 Pro Max, the iPhone Air and the iPhone 18 Pro. On any Apple Intelligence iPhone, assign it to the Action Button, or add its button to the Lock Screen or Control Center. The iPhone 15 Pro has no Camera Control, so one of the other three is the route there. With the Siri AI beta on, Apple adds the Camera app as a fifth way in.

Put ChatGPT on the Action Button, Lock Screen and Home Screen

The fastest way to open ChatGPT on iPhone is a physical button. Apple does not let another assistant take over the Side button, as MacRumors notes. The Action Button on an iPhone 15 Pro or later is the workaround: one press opens ChatGPT Voice.

Set the Action Button to ChatGPT Voice

1. Install the ChatGPT app and sign in.
2. Open Settings and tap Action Button.
3. Swipe to Controls and tap the button below it.
4. Search for "ChatGPT" and choose Open ChatGPT Voice.
5. Press and hold the Action Button. Allow microphone access the first time.

Apple lists the Action Button on the iPhone 15 Pro and 15 Pro Max and on every iPhone 16 model, including the iPhone 16e. The iPhone 17, 17 Pro, 17 Pro Max, iPhone Air and iPhone 18 Pro have it too. One limit to know: ChatGPT cannot do Siri's system jobs, such as setting an alarm or adding a calendar event, as MacRumors points out in its setup guide.

Widgets and Lock Screen Controls

ChatGPT also has Home Screen widgets and Lock Screen controls. MacStories reported in August 2026 on a newer widget, ChatGPT shortcuts, in small and medium sizes. You pick which buttons it shows, such as New chat, Camera, Photos, Dictation and Voice. To add one, edit your Home Screen, add a widget and search for ChatGPT. MacStories also describes ChatGPT voice controls in Control Center and on the Lock Screen, so a voice chat is one tap away even without an Action Button.

How to Use ChatGPT on iPhone Without the App

You can use ChatGPT on iPhone without installing anything, in three ways: Safari, a phone call, or WhatsApp in Europe. These routes suit an older iPhone that cannot run iOS 18, or a borrowed phone.

Safari: open chatgpt.com and type. OpenAI lets you chat before creating an account, but only one conversation at a time, and nothing is saved unless you log in. OpenAI's help center says logged-out use is not yet available in Europe, apart from the UK.

Phone call: dial 1-800-CHATGPT (1-800-242-8478) from a US or Canadian number. No account is needed, and OpenAI gives you 30 minutes a month for free.

WhatsApp: most guides say ChatGPT left WhatsApp on 15 January 2026, after a WhatsApp policy change.

That is now only half true. OpenAI's help center says ChatGPT is available again on WhatsApp in the European Economic Area. You message the verified 1-800-CHATGPT contact at +1-800-242-8478, and eligibility depends on the country code of your WhatsApp number. Usage limits apply, and the rollout is gradual. Details are on OpenAI's 1-800-ChatGPT help page.

Use ChatGPT Alongside Claude and Gemini With Fello AI

Siri's only built-in chatbot extension is ChatGPT, so the Apple route locks you into one model. Fello AI puts GPT, the models behind ChatGPT, in one iPhone app next to Claude, Gemini, Grok, Perplexity, DeepSeek, Kimi, GLM and Qwen. You pick the model per chat, so you can ask GPT, then ask Claude the same question when the first answer misses.

Fello AI does more than chat. It searches the web, reads PDFs and Word files, generates images, and builds real PowerPoint decks and Excel sheets on your phone. You can talk to it with your voice, and the same app runs on Mac and iPad.

Fello AI runs on iOS 16 or later, two versions below the ChatGPT app's iOS 18 requirement, so it works on older iPhones that cannot install iOS 18. It has a free tier and a 4.7 out of 5 average rating worldwide. For the other ChatGPT clients and AI apps worth installing, see our ranking of the best AI apps for iPhone.

Conclusion

Start with the official ChatGPT app. It is free, it has every feature, and it is the only route that keeps your history in one place. If your iPhone has Apple Intelligence, turn on the ChatGPT extension in Settings, then Siri, so "ask ChatGPT" works hands-free. Then put ChatGPT Voice on the Action Button, which turns a long press into the quickest assistant on the phone. Pay for Plus only when you hit the Free plan's voice, upload or image limits. And if you want ChatGPT's answers checked against Claude or Gemini without three subscriptions, use Fello AI.

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