CLAUDE.md vs GEMINI.md vs Cline rules vs .cursorrules
Every comparison page on the web is a capability table someone wrote from the vendor docs in an afternoon. None of them can tell you how many real repositories ship each file, how long the median one runs, or how often two of them turn up in the same project. Those answers need a corpus, and RuleStack counts one every night.
| Format | CLAUDE.md 2026-08-02 | GEMINI.md 2026-08-01 | Cline rules 2026-08-01 | .cursorrules 2026-08-02 |
|---|---|---|---|---|
| Asserted — what the docs say it can express | ||||
| File | CLAUDE.md | GEMINI.md | .clinerules | .cursorrules |
| Status | vendor | vendor | vendor | deprecated |
| Cross-tool | No | No | No | No |
| Tools that read it |
|
|
|
|
| Frontmatter | No | No | No | No |
| Glob targeting | No | No | No | No |
| Imports other files | Yes | Yes | No | No |
| Nested / per-directory | Yes | Yes | No | No |
| Multiple files | Yes | Yes | Yes | No |
| User-level scope | Yes | Yes | Yes | No |
| When it applies | Always in scope. Project file, plus nested files in subdirectories, plus a user-level file (~/.claude/CLAUDE.md) that applies across every project. | Hierarchical memory: a global ~/.gemini/GEMINI.md, then the project file, then nested files, concatenated from broadest to narrowest. | Always in scope. Either a single .clinerules file or a .clinerules/ directory whose markdown files are all loaded. | Always in scope, single file at the repo root. |
| Size limits | None | None | None | None |
| Measured — counted from real repositories on 2026-08-04 | ||||
| Repositories carrying it | 248 | 33 | 79 | 27 |
| Share of indexed repos | 35.5% | 4.7% | 11.3% | 3.9% |
| Files indexed | 775 | 46 | 305 | 308 |
| Median length (words) | 2,042 | 257 | 262 | 366 |
| 90th percentile length | 2,998 | 1,704 | 1,412 | 1,104 |
| Files naming commands | 34.2% | 52.2% | 34.1% | 13.6% |
| Files containing code | 34.5% | 45.6% | 33.1% | 25.0% |
| Median quality score | 44 | 60 | 54 | 41 |
| Median repository stars | 114 | 11,320 | 1 | 26 |
How often they turn up together
A capability table cannot answer this at all. Of the repositories carrying the first format, this is the share that also carry the second — counted, both directions, on 2026-08-04.
GEMINI.md + Cline rules
2026-08-047
repositories carry both. That is 21.2% of everything with GEMINI.md, and 8.9% of everything with Cline rules.
.cursorrules + GEMINI.md
2026-08-044
repositories carry both. That is 14.8% of everything with .cursorrules, and 12.1% of everything with GEMINI.md.
.cursorrules + Cline rules
2026-08-043
repositories carry both. That is 11.1% of everything with .cursorrules, and 3.8% of everything with Cline rules.
CLAUDE.md + GEMINI.md
2026-08-0417
repositories carry both. That is 6.9% of everything with CLAUDE.md, and 51.5% of everything with GEMINI.md.
CLAUDE.md + .cursorrules
2026-08-0410
repositories carry both. That is 4.0% of everything with CLAUDE.md, and 37.0% of everything with .cursorrules.
CLAUDE.md + Cline rules
2026-08-0425
repositories carry both. That is 10.1% of everything with CLAUDE.md, and 31.6% of everything with Cline rules.
What each one is for
CLAUDE.md
2026-08-02Claude Code's memory file. Shaped like AGENTS.md but with two things it lacks: @path imports, so shared rules live in one place, and a user-scope layer that follows the developer across repos rather than shipping with the code.
Strengths
- @path imports — shared conventions written once and pulled into each file
- A user-scope file lets personal preferences live outside the team repo
- Nested project files compose with the root file rather than replacing it
Weaknesses
- Single-vendor: no other agent reads it, so multi-tool teams maintain two files
- No glob targeting, same context cost as AGENTS.md — path-scoped rules exist, but in a separate .claude/rules/ file, not in CLAUDE.md itself
GEMINI.md
2026-08-01Gemini CLI's memory file, structurally close to CLAUDE.md — @imports and a user-scope layer — which is why repos that carry both usually carry near-identical text in each.
Strengths
- @path imports and a global user file, same composition model as CLAUDE.md
- Explicit hierarchy from global to local
Weaknesses
- Google-only
- No glob targeting
Cline rules
2026-08-01A single file or a folder of files, all always-on. The folder form is the simplest way any format here lets you split rules into topics without also learning an activation model.
Strengths
- Directory form splits rules by topic with zero configuration
- Toggleable rule sets for switching context between tasks
Weaknesses
- Cline-only
- Everything is always-on — no targeting, so the folder form costs context
.cursorrules
2026-08-02Cursor's original single-file format, superseded by .cursor/rules/*.mdc. Tracked here precisely because it is dead: how much of the ecosystem is still shipping a deprecated file is a measurable answer, and a large share of the "best cursor rules" pages on the web still teach this format.
Strengths
- One file, nothing to configure
Weaknesses
- Deprecated — do not start here
- No targeting, no composition, no metadata
