How to choose between JetBrains AI Assistant and GitHub Copilot
Choose between JetBrains AI Assistant and GitHub Copilot by the editor people already open, where a diff is reviewed, and who approves a command. Current docs list Copilot agent mode for JetBrains IDEs, and JetBrains documents Copilot as a third-party agent inside AI Assistant. Neither page ranks the two. Write the choice against the workflow.
On this page
Start from the editor already open
Note which editor people already open. An entry point reaches the short list only when it matches that editor: where the diff is reviewed, who may approve a terminal command, and which paths stay excluded. Leave those three unwritten and it is too early to compare the products.
If the team already delivers through Custom software, websites, and applications, the tool has to leave its diff in the review you already run. Changing the editor does not change the reviewer or the rule for the main branch. The Cursor comparison is in How to choose between Cursor and GitHub Copilot. This note covers teams already on a JetBrains IDE, and Copilot’s entry points across editors.
What AI Assistant does in a JetBrains IDE
The current About AI Assistant page describes AI Assistant as a collection of AI-powered features and coding agents integrated into JetBrains IDEs. The page lists context-aware AI Chat, coding agents for multi-step tasks across files, in-editor help that generates or updates code from natural language plus inline completion and next-edit suggestions, explanations and refactoring suggestions, and generation of documentation, unit tests, commit messages, and pull request summaries.
The same page lists CLion, DataGrip, DataSpell, GoLand, IntelliJ IDEA, PhpStorm, PyCharm, Rider, RubyMine, RustRover, and WebStorm. It also names Android Studio and ReSharper, and says this documentation covers JetBrains IDEs only. Activation can be a JetBrains AI subscription, your own API keys, a provider account for an integrated agent, or an external coding agent you install. The page has no publication date; the description above follows the current text. The page also has a step for choosing a model. This note does not compare models.
How Copilot connects inside JetBrains
The current GitHub Copilot page in the JetBrains docs describes GitHub Copilot as a third-party coding agent available in AI Assistant. Activation is only through a GitHub account with OAuth. A JetBrains AI subscription or your own key does not replace that sign-in, even when JetBrains AI is already on. The page says Copilot does not follow AI Assistant’s `.aiignore`, so files listed there can still be processed, and that Copilot does not work in Remote Development sessions because the remote environment cannot open a browser to finish the GitHub login.
The same page says that with automatic context on, each request includes the file open in the editor and any text selected in that file. Other open files, recently edited files, and wider project context are not attached on their own; you add them with `@`. Three modes are listed: Agent can read and modify files and run commands; Plan is read-only and produces a structured plan before changes; Autopilot works through a multi-step task without pausing between steps. Autopilot controls that pause, and permission stays separate: unless Allow All is on, Copilot still asks before an action that needs permission, including in Autopilot. With Allow All on, tool use, path access, and opening a URL proceed without a fresh approval; the page says to use that setting with caution because the agent can act without approval and that may lead to data loss or security issues. With it off, the choices are Allow once, Always allow, or Deny. The page also says Copilot reads instructions from `AGENTS.md` and `CLAUDE.md` in the project root, so those files can live in version control.
Agent mode and plan mode in Copilot’s docs
The current page on agent mode in the IDE says agent mode takes a high-level task, decides which files to change, edits them, and runs commands until the task is done. You review the changes, and by default you approve commands before they run. An administrator or an editor setting may allow some commands to run on their own. The page lists Visual Studio Code, Visual Studio, JetBrains IDEs, Xcode, and Eclipse. If Agent is missing from the menu, an administrator may have turned the mode off. Each prompt consumes GitHub AI Credits. This note does not quote a price for credits or a plan. The page has no publication date.
The current page on plan mode in the IDE says the plan agent researches the task with read-only tools and makes no code changes until you approve. After approval, Start Implementation switches to agent mode, or Open in Editor saves the plan as Markdown. The page lists Visual Studio Code, JetBrains IDEs, Xcode, and Eclipse, and says plan mode is not currently available in Visual Studio. On some editor tabs the page notes that plan mode is in public preview and subject to change.
Review, approval, and excluded files
Before adoption, write three things: who reviews a diff, which commands must stop for a person, and which paths Copilot may still read after they are listed in `.aiignore`. The third item comes from the JetBrains page: `.aiignore` does not apply to GitHub Copilot. Secrets and credentials need a separate exclusion. How to draw the directories is covered in How to connect an AI coding tool to an existing codebase.
Allow All, and the GitHub wording that some commands may run on their own, are the two switches in the current docs that loosen approval. Keep the default of approving each time. Leave out any command that installs a dependency, pushes to a remote, changes a database, or deletes files. The person who approves sees the full command.
Choose from the workflow you already run
When the team already works in one of the JetBrains IDEs listed above, and review already happens on the diff in that IDE, start from AI Assistant’s chat, in-editor help, and coding agents. To use GitHub Copilot in that same IDE, complete the separate GitHub sign-in the JetBrains page describes, and record that `.aiignore` does not apply and that Remote Development cannot activate Copilot. Write down whether people open Copilot inside AI Assistant or Copilot Chat’s own agent mode, because the two pages describe different approval switches.
When the team already works in Visual Studio Code, Visual Studio, Xcode, or Eclipse, follow GitHub’s agent-mode page. That page’s list also includes JetBrains IDEs. When the team wants a plan before any edit, the plan-mode page says Visual Studio does not currently offer that mode. This note does not call any combination the better one. How autocomplete and an agent split a task is covered in What is the difference between an AI coding agent and autocomplete.
When to leave the choice for later
If the reviewer, the command-approval rule, and the excluded directories are still unwritten, leave every agent off a repository that can change the main branch. Write those three first. A small edit inside a file you already have open can stay with in-editor completion.
This note does not compare speed, defects, or licence cost. The JetBrains and GitHub pages cited above have no publication date; the quotations follow the current official text. Until you have your own review record, check the choice by whether the editor is the one people already open, whether the diff entered review, and whether commands were approved under the rule.