ChatGPT and Claude in one app: 6 routes priced and compared

What carries over when ChatGPT and Claude share one app?

In one app the conversation carries over: the next model reads the thread, the project's files and instructions travel with every message, and both vendors' old chats can sit in one sidebar. Each vendor's own tools stay behind. In two separate apps nothing carries over on its own. The table compares the two setups line by line, checked against Anthropic's help center and Whizi's code on 3 October 2026.

The bottom two rows are where a shared thread loses to Claude's own app. Anthropic's help center, read 3 October 2026, gives Claude Fable 5.1, Opus 5.5, Opus 5, Sonnet 5.5 and Sonnet 5 a 1M token window in paid chats. Fable 5, Opus 4.6 to 4.8 and Sonnet 4.6 get 500K, and the rest get 200K. A Whizi turn sends at most 40,000 input tokens of the thread, and proportionally less on a model with a small window. So the oldest turns of a very long conversation are the first to drop. For a whole book or a large codebase in one sitting, you'll want Claude's own app. For the everyday handoff, where GPT drafts and Claude edits the draft above it, 40,000 tokens covers the thread with room to spare.

Can ChatGPT and Claude work together in one conversation?

Yes, but only inside an app that holds both models. ChatGPT runs OpenAI's models and Claude runs Anthropic's, so the two native apps always keep two separate threads. In an aggregator app you change the model in the picker between messages, and the new model reads everything the old one wrote, including its answers. On Whizi, switching mid-conversation sends the existing thread to the newly selected model, and nothing goes to a model you didn't pick.

Each turn is billed at the rate of the model that answers it. On Whizi Pro, a GPT-5.6 Terra answer costs 4 credits, a Claude Sonnet 5 answer 10 and a GPT-5.6 Sol answer 20, all drawn from the plan's 2,500 credits a month. So the common pattern, a draft in GPT and an edit in Claude, costs 14 credits on Terra and Sonnet. The pattern is set out step by step in switching models mid-conversation.

One habit makes the second model useful. It sees the first model's answer as part of the conversation and tends to agree with it, so ask for independence in so many words:

Evaluate the answer above on its merits, as if a stranger wrote it. List factual errors, missing steps and weak assumptions. If it holds up, say so in one line.

Running both models on one prompt at the same moment is a different feature from switching. On Whizi it's compare mode, two columns with separate follow-ups. It's on Pro and Powerhouse, billed at the sum of both models' rates. The guide to comparing models side by side covers it.

Which apps put ChatGPT and Claude in one place, and what do they cost?

Six routes put GPT and Claude within one login. They split into general chat apps, a work suite and a coding tool. Every price below is from the vendor's own page, in US dollars, as of 3 October 2026, except MultiChats, whose price is from its own blog post of 4 June 2026.

Microsoft's route is the oldest of the big ones. Its 24 September 2025 announcement brought Anthropic models into Microsoft 365 Copilot through the Researcher agent and Copilot Studio. Message Center post MC1247880 then rolled Claude into Copilot Chat for licensed users by early April 2026. Admins in the EU, EFTA and the UK find it switched off by default. It's a route for people whose employer buys it, not one an individual can sign up for. GitHub's plan page lists the same Claude and GPT models on Free, Pro, Pro+ and Max. The plans differ in credits, not in models.

Two phone apps also sit on page one for this search, ChatOn and ChatBuddy. They sell the same idea through app store subscriptions, and we didn't price them. Bring-your-own-key clients and self-hosted options are a third shape of the same category, and the all-in-one AI platforms roundup compares all three.

Is ChatGPT and Claude in one subscription cheaper than paying for both?

Yes on the bill, and no for anyone who sends Claude more than about 250 messages a month. ChatGPT Plus is $20 a month per OpenAI's help center (quoted in a search snippet on 3 October 2026; the page blocks direct fetches) and Claude Pro is $20 per Anthropic's pricing page, so both cost $40. Whizi Pro is $29.99, or $19.99 a month billed yearly.

The catch is metering. Whizi Pro carries 2,500 credits a month, and a Claude Sonnet 5 answer costs 10, so a month of nothing but Claude Sonnet is 250 answers, about 8 a day. A GPT-5.6 Terra answer costs 4, so the same month on Terra is 625. A typical split of 150 Claude edits and 250 Terra drafts spends exactly the 2,500. The rule is plain. If Claude is your main tool all day, pay Anthropic directly. If Claude is the second model you reach for, to edit or check what GPT produced, one app costs less and keeps both in one thread. The two subscriptions question has a one-week test for telling which you are.

What does one app lose against the two native apps?

One app loses the vendors' own products. Claude Pro includes Claude Code, per Anthropic's pricing page, and ChatGPT Plus includes Codex, per OpenAI's Codex pricing page. Neither comes with a third-party app, which sells model access and nothing else. Claude's 1M token chats lose to a 40,000 token turn whenever the whole document has to be read at once.

Whizi loses in three more places. The top models cost more: Claude Fable and GPT-6 Astra are Powerhouse only, at $49.99 a month, and cost 100 credits a message, while Claude Opus costs 20 on Pro. A free account can't open GPT at all. It reaches Whizi AI, Auto and Claude Haiku 5.5 only. And your ChatGPT custom instructions don't import, so you paste them again, into a project or into an always-on Skill that applies to every chat (up to 30 Skills of 4,000 characters each, 5 active in one chat).

Keep the two native apps if you live in Claude Code or Codex, if your work means one enormous document per session, or if you send one vendor hundreds of messages a week. Take one app if your real pattern is a draft in one model and a second look in the other, and the cost of keeping two histories in step is the part you want gone.

How do you move ChatGPT and Claude history into one app?

Export from each vendor, import both files, then rebuild the one thing an import cannot carry: your instructions. The order is the same in any app that imports both:

1. Request the data export in ChatGPT and in Claude, and download each file.
2. Import each file into the new app. On Whizi the screens are in the guides for importing ChatGPT chats and importing Claude chats.
3. Check what arrived. Imports usually keep the visible text and drop reasoning, tool calls and attachments.
4. Paste your custom instructions into a project or the app's standing instructions; no export carries them. Whizi's version is setting up a project.

Memory doesn't travel in any export. To carry what ChatGPT knows about you, ask it in a new chat:

List everything you have stored about me and my work: preferences, ongoing projects, tools I use and how I like answers formatted. One fact per line, no commentary.

Paste the result into a Whizi project's instructions, or into Claude's own importer if Claude is where you're moving. Anthropic's import article, updated 2 September 2026, puts the importer on the Free, Pro, Max and Team plans on the web and Claude Desktop. Anthropic calls imports "experimental and still in active development". It says the updated memory appears "shortly after" on Claude's new memory experience and within 24 hours on the legacy one. It also warns that "Claude may not retain imported personal details unrelated to work."