ChatGPT deep research vs Gemini Deep Research vs Perplexity vs Claude Research: which should you use?

Every major AI assistant now has a mode that goes away for a few minutes, reads dozens or hundreds of web pages and comes back with a long, cited report. OpenAI calls it deep research, Google calls it Deep Research, and Perplexity and Anthropic both call it Research. They look similar on the surface, but they differ on who gets them free, what sources they can read and how much control you have. This comparison uses each company’s own help and pricing pages as of October 2026. It compares documented features and limits; we haven’t run the same research task through all four.

The short answer

• Choose Gemini Deep Research if you don’t want to pay, or your work lives in Gmail and Drive. It shows you a research plan to edit before it starts.
• Choose ChatGPT deep research if you want control over exactly which websites it uses, or you need Word and PDF downloads. Plus, at $20 a month, raises the limit from “limited” to “expanded”.
• Choose Perplexity Research for quick, web-only reports on topics such as finance, current affairs or travel. Perplexity says most tasks finish in under 3 minutes, the shortest time any of the four quotes.
• Choose Claude Research if you already pay for Claude and want research that pulls in your email, calendar, documents and other connectors.

Side by side

Prices are US list prices from each company’s pricing page in October 2026. OpenAI’s pricing page didn’t show a price for ChatGPT Go when we checked, and Perplexity’s showed only annual prices. Gemini’s plan multipliers (2x Free on AI Plus, 4x on AI Pro, 5x or 20x Pro on Ultra) are Google’s general usage limits, and Google says Deep Research uses more of them than ordinary chat.

How each one works

ChatGPT deep research

Start it by typing /Deepresearch, choosing Deep research from the + tools menu, or picking it from the sidebar. ChatGPT may ask clarifying questions, then proposes a research plan you can edit. While it runs you can watch progress and interrupt it to change focus or sources. By default it searches the public web and your uploaded files. It can also use supported connected apps, such as Google Drive or SharePoint, but only their read actions, never write actions.

The standout control is Sites > Manage sites: you can restrict research to the domains you list, or prioritize them while still searching the wider web. Finished reports open full screen with a table of contents, a sources section and an activity history, and download as Markdown, Word or PDF. OpenAI’s pricing page lists deep research as limited on Free and Go, expanded on Plus and maximum on Pro, without published numbers; your in-product counter shows what’s left. OpenAI also says availability depends on your plan and country. See ChatGPT Go vs Plus and ChatGPT Pro explained for the plans.

Gemini Deep Research

On gemini.google.com, click Add Files, then Deep Research, type your question and submit. Gemini writes a research plan; click Edit plan to change it, then Start research. Google Search is a source by default, and the Sources menu adds Gmail and Drive (once Google Workspace is connected), uploaded files and notebooks from Gemini Notebook, formerly NotebookLM. Deselect Google Search to research only your own material.

Google says reports usually take 5 to 10 minutes, and it notifies you when one is ready. From the Canvas panel you can create an Audio Overview, build a custom visualization, export to Google Docs, copy the text or share it. On AI Ultra, reports can include charts, diagrams and interactive simulators, but not when Gmail or Drive is a source. You must be 18 or over, and past reports only stay findable if Keep Activity is on. See Google AI Plus vs Pro vs Ultra for what each plan adds.

Perplexity Research

Pick Research from the mode selector in the search box, on the web, the mobile apps or the Mac app. Perplexity says Research “performs dozens of searches, reads hundreds of sources” and reasons through them, using search and code to refine its plan as it learns. Its help pages describe newer touches: clarifying questions for broad queries, follow-up questions you can add while research is still running, a live view of which sources it’s reading, and key findings that appear before the final report.

Reports export to PDF or a document, or become a shareable Perplexity Page. You can’t choose the model. Perplexity’s plan comparison lists one Research query a month on Free and “monthly limits” on Pro and Max, with Max described for advanced use and higher Deep Research limits. Enterprise Pro gets 50 a month and Enterprise Max 500. For the basics of the app, see our Perplexity profile and Perplexity vs ChatGPT.

Claude Research

Web search must be on. Click + at the bottom left of the chat, then Research; a blue indicator shows it’s active. Anthropic says Claude “runs multiple searches that build on each other and decides what to look into next based on what it finds.” It searches the web plus your connected tools, including Gmail, Google Calendar and Google Docs, and can use connector tools without asking each time. There’s an important catch: started from the Claude mobile app, Research searches only the web and silently skips your connectors. It also can’t use local MCP servers set up in Claude Desktop.

Research works on Pro, Max, Team and Enterprise, on the web, desktop and mobile. It counts against the same usage limits as normal chats but uses them faster. It always runs on Claude Opus 5.5, falling back to Opus 4.8, whichever model you’ve selected. If Claude doesn’t start researching, Anthropic suggests asking it directly to “use the research tool”. See how to use Claude and Claude Pro vs Max.

Which should you use?

• You don’t want to pay: Gemini, which includes Deep Research on the free plan with daily limits. ChatGPT Free is also limited, and Perplexity Free gives one query a month.
• You need reports from your own email and files: Gemini for Gmail and Drive, Claude for a wider set of connectors on a paid plan, ChatGPT for supported apps such as Drive and SharePoint.
• You need to control or audit sources: ChatGPT, for the site restrictions and the activity history in every report.
• You want something quick: Perplexity, which says most tasks finish in under three minutes.
• You’re writing up a report for colleagues: ChatGPT for Word and PDF files, or Gemini for a Google Doc.

Whichever you use, treat the report as a well-organized first draft. Open the cited sources for anything that matters, and watch for old pages and numbers taken out of context. For a wider view of the assistants, read ChatGPT vs Claude vs Gemini, and for agents that keep working after the report is done, see ChatGPT dots vs Gemini Spark vs Claude Cowork.