Real files, at real paths, counted every nightCounted 08:17 UTCDiff two files
7,205instruction files1,198repositories visited4,189rows written36files changed8formats20section tags85stacksCounted 13 September 2026
Cursor rulescursor.comCopilot instructionsgithub.com

Cursor rules vs Copilot instructions

The same 6 criteria for both, with the page each figure came from and the day it was read.

6 criteria2 formatsRead 13 September 2026
The short answer

Which one, and when

On where the file lives, Cursor rules is .cursor/rules/*.mdc and Copilot instructions is .github/copilot-instructions.md. On per-directory files, Cursor rules is Folders inside .cursor/rules, for organisation and Copilot instructions is No, extra files stay under .github/instructions. On path-scoped rules, Cursor rules is Yes, globs, description or @-mention and Copilot instructions is Yes, applyTo glob in frontmatter. On what wins on a conflict, Cursor rules is Team rules take precedence and Copilot instructions is Personal, then repository, then organisation. On published size guidance, Cursor rules is Under 500 lines per rule and Copilot instructions does not publish it. On what its own docs say about rival formats, Cursor rules is Names AGENTS.md as the plain-markdown option and Copilot instructions is Documents AGENTS.md, CLAUDE.md and GEMINI.md as alternatives. RuleStack sells neither of these and takes no referral fee on either, it scores them. Every figure was read off the named company's own page on or since 2026-09-13; the URLs and the dates are at the foot of this page, and a job re-fetches each one on a schedule and fails when a figure is no longer on the page it came from.

Asserted

Cursor rules vs Copilot instructions, row by row

Read 13 September 2026
Criterion
Cursor rulescursor.com
Where the file lives
.cursor/rules/*.mdc"Project rules live in .cursor/rules as .mdc files and are version-controlled." A plain .md file in that directory is ignored: "api-guidelines.md # ignored (wrong extension)".cursor.com, read 13 September 2026
.github/copilot-instructions.md"Repository-wide custom instructions apply to all requests made in the context of a repository. These are specified in a copilot-instructions.md file in the .github directory of the repository."docs.github.com, read 13 September 2026
Per-directory fileswhether the format documents putting a second file next to the code it governs, rather than one file at the repository root
Folders inside .cursor/rules, for organisationThe documented layout puts subfolders inside the one rules directory, "frontend/ # organize rules in folders", rather than a rules directory beside each package. For per-directory files Cursor's own page points elsewhere: "Cursor supports AGENTS.md in the project root and subdirectories."cursor.com, read 13 September 2026
No, extra files stay under .github/instructionsThe additional files are centralised rather than placed beside the code: they are "specified in one or more NAME.instructions.md files within or below the .github/instructions directory in the repository", and are aimed at code by glob instead of by location. Per-directory files are documented on the same page under a different format, "you can create one or more AGENTS.md files, stored anywhere within the repository".docs.github.com, read 13 September 2026
Path-scoped ruleswhether a rule can be limited to files matching a pattern instead of loading into every request, which is the mechanism that decides how much of your context window the file costs
Yes, globs, description or @-mentionFour documented rule types. "Apply to specific files When file matches a specified pattern", and the frontmatter table spells out what each combination of alwaysApply, description and globs does.cursor.com, read 13 September 2026
Yes, applyTo glob in frontmatter"At the start of the file, create a frontmatter block containing the applyTo keyword. Use glob syntax to specify what files or directories the instructions apply to." Multiple patterns are comma-separated, and excludeAgent narrows which Copilot feature reads the file.docs.github.com, read 13 September 2026
What wins on a conflict
Team rules take precedence"Team rules work alongside other rule types and take precedence to ensure organizational standards are maintained across all projects." Admins can also mark a rule enforced, which means it "cannot be disabled in Customize".cursor.com, read 13 September 2026
Personal, then repository, then organisation"Personal instructions take the highest priority. Repository instructions come next, and then organization instructions are prioritized last. However, all sets of relevant instructions are provided to Copilot." This is the only one of the five whose stated order puts the individual above the repository.docs.github.com, read 13 September 2026
Published size guidance
Under 500 lines per rule"Keep rules under 500 lines", with the follow-on advice to "split large rules into multiple, composable rules".cursor.com, read 13 September 2026
Not publishedThis page publishes no line count, byte budget or context-cost guidance for copilot-instructions.md. It describes the format and its precedence rules and says nothing about how long the file should be.docs.github.com, read 13 September 2026
What its own docs say about rival formats
Names AGENTS.md as the plain-markdown option"If you prefer plain markdown, use AGENTS.md instead." The page lists AGENTS.md as a rule type of its own, "Simple alternative to .cursor/rules", and documents nested AGENTS.md support in subdirectories.cursor.com, read 13 September 2026
Documents AGENTS.md, CLAUDE.md and GEMINI.md as alternatives"You can create one or more AGENTS.md files, stored anywhere within the repository. When Copilot is working, the nearest AGENTS.md file in the directory tree will take precedence … Alternatively, you can use a single CLAUDE.md or GEMINI.md file stored in the root of the repository."docs.github.com, read 13 September 2026

Every figure was read off the named company's own page on or since 13 September 2026. A job re-fetches each URL on a schedule and fails when a figure is no longer on the page it came from.

When to pick each

One paragraph per format, in its own terms

Pick Cursor rules when

You want a rule that only loads when it is relevant, and you want the agent, not a glob you maintained by hand, to make that call. Cursor is the only one of the five whose docs publish the full decision table for when a rule is included: `alwaysApply: true` always, a `globs` pattern on a file match, a `description` alone when "agent reads the description and pulls the rule in when relevant", and nothing at all until you @-mention it. Nobody else documents a description-triggered rule, and on a large repository that is the difference between five rules in context and fifty.

Pick Copilot instructions when

The instructions have to apply on github.com and not only in an editor, pull-request review, the cloud agent, chat on the repository page. Copilot's is the only one of the five documented as a server-side repository setting rather than a file a local tool happens to read, and the only one with a documented way to aim a rule at one Copilot feature and not another: `excludeAgent: "code-review"`, which the page says makes a file "only be read by Copilot cloud agent".

The questions that follow

One question, one answer, nothing collapsed

Cursor rules vs Copilot instructions, where the file lives?

Cursor rules: .cursor/rules/*.mdc. "Project rules live in .cursor/rules as .mdc files and are version-controlled." A plain .md file in that directory is ignored: "api-guidelines.md # ignored (wrong extension)". Copilot instructions: .github/copilot-instructions.md. "Repository-wide custom instructions apply to all requests made in the context of a repository. These are specified in a copilot-instructions.md file in the .github directory of the repository.". Read from cursor.com and docs.github.com on 2026-09-13.

Cursor rules vs Copilot instructions, per-directory files?

Cursor rules: Folders inside .cursor/rules, for organisation. The documented layout puts subfolders inside the one rules directory, "frontend/ # organize rules in folders", rather than a rules directory beside each package. For per-directory files Cursor's own page points elsewhere: "Cursor supports AGENTS.md in the project root and subdirectories.". Copilot instructions: No, extra files stay under .github/instructions. The additional files are centralised rather than placed beside the code: they are "specified in one or more NAME.instructions.md files within or below the .github/instructions directory in the repository", and are aimed at code by glob instead of by location. Per-directory files are documented on the same page under a different format, "you can create one or more AGENTS.md files, stored anywhere within the repository". Read from cursor.com and docs.github.com on 2026-09-13. Per-directory files here means whether the format documents putting a second file next to the code it governs, rather than one file at the repository root.

Cursor rules vs Copilot instructions, path-scoped rules?

Cursor rules: Yes, globs, description or @-mention. Four documented rule types. "Apply to specific files When file matches a specified pattern", and the frontmatter table spells out what each combination of alwaysApply, description and globs does. Copilot instructions: Yes, applyTo glob in frontmatter. "At the start of the file, create a frontmatter block containing the applyTo keyword. Use glob syntax to specify what files or directories the instructions apply to." Multiple patterns are comma-separated, and excludeAgent narrows which Copilot feature reads the file. Read from cursor.com and docs.github.com on 2026-09-13. Path-scoped rules here means whether a rule can be limited to files matching a pattern instead of loading into every request, which is the mechanism that decides how much of your context window the file costs.

When should I pick Cursor rules, and when Copilot instructions?

Cursor rules, You want a rule that only loads when it is relevant, and you want the agent, not a glob you maintained by hand, to make that call. Cursor is the only one of the five whose docs publish the full decision table for when a rule is included: `alwaysApply: true` always, a `globs` pattern on a file match, a `description` alone when "agent reads the description and pulls the rule in when relevant", and nothing at all until you @-mention it. Nobody else documents a description-triggered rule, and on a large repository that is the difference between five rules in context and fifty. Copilot instructions, The instructions have to apply on github.com and not only in an editor, pull-request review, the cloud agent, chat on the repository page. Copilot's is the only one of the five documented as a server-side repository setting rather than a file a local tool happens to read, and the only one with a documented way to aim a rule at one Copilot feature and not another: `excludeAgent: "code-review"`, which the page says makes a file "only be read by Copilot cloud agent".