Claude Code vs Gemini Code AssistComparisonUpdated 2026-03-18
SUMMARY
Claude Code (CLI) uses markdown configuration while Gemini Code Assist (IDE) uses markdown. They differ on 4 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.
FEATURE COMPARISON
| Feature | Claude Code | Gemini Code Assist |
|---|---|---|
| Config format | markdown | markdown |
| Hierarchy support | ✓ | ✓ |
| Global config | ✓ | ✗ |
| Project config | ✓ | ✓ |
| Subdirectory scoping | ✓ | ✓ |
| File inclusion / imports | ✓ | ✗ |
| Ignore file | .claudeignore | ✗ |
| IDE integration | CLI | ✓ |
| Schema / structure | Free-form (Markdown) | Free-form (Markdown) |
| Git committed | ✓ | ✓ |
| Encoding | UTF-8 | UTF-8 |
FILE MAPPING
| Purpose | Claude Code | Gemini Code Assist |
|---|---|---|
| Project instructions | CLAUDE.md | GEMINI.md |
SIDE-BY-SIDE CODE SAMPLES
Claude Code
CLAUDE.md
markdown
# Project Name
> TypeScript + React monorepo. Deployed on Vercel.
## Code Style
- TypeScript strict mode — no `any`, no `ts-ignore`
- Named exports only (no default exports)
- Prefer functional patterns: map/filter/reduce over for-loops
- Error handling: use Result<T, E> from `src/lib/result.ts`
## Architecture
- `src/routes/` — Route handlers (thin layer, delegates to services)
- `src/services/` — Business logic, one file per domain entity
- `src/db/` — Drizzle ORM schema and query helpers
- `src/lib/` — Shared utilities (logger, result type, validation)
## Commands
```bash
pnpm install # Install dependencies
pnpm dev # Start dev server (port 3000)
pnpm test # Run Vitest suite
pnpm test:e2e # Run Playwright tests
pnpm lint # ESLint + Prettier check
pnpm db:migrate # Run pending Drizzle migrations
```
## Git Conventions
- Conventional Commits: `feat:`, `fix:`, `chore:`, `docs:`
- Branch naming: `feat/short-description`, `fix/issue-number`
- Squash merge to main; delete branches after merge
## Notes
- The `src/legacy/` directory is being migrated. Do not add new code there.
- All dates are stored as UTC. Never use local time.
@docs/api-patterns.md
@docs/database-conventions.md
Gemini Code Assist
GEMINI.md
markdown
# Project Rules
## Overview
E-commerce platform built with Go microservices and React frontend.
All services communicate via gRPC with Protocol Buffers.
## Go Services
- Follow standard Go project layout (cmd/, internal/, pkg/)
- Use structured logging with slog (not log or fmt.Println)
- Error handling: always wrap errors with fmt.Errorf("%w", err)
- Database access through repository pattern in internal/repo/
- All public functions must have godoc comments
## API Design
- Proto files live in proto/ directory with buf for linting
- Use field masks for partial updates
- Pagination via cursor-based tokens, not offset
## Testing
- Table-driven tests for all business logic
- Use testcontainers-go for integration tests
- Minimum 80% coverage on internal/ packages
- Mock external services with gomock interfaces
## Do Not
- Use global variables or init() functions
- Import internal packages across service boundaries
- Commit generated .pb.go files (CI generates them)
KEY DIFFERENCES
Claude Code: Supported. Gemini Code Assist: Not supported.
Claude Code: Supported. Gemini Code Assist: Not supported.
Claude Code: .claudeignore. Gemini Code Assist: Not supported.
Claude Code: CLI. Gemini Code Assist: Supported.
WHICH SHOULD I USE?
Choose based on your IDE/CLI preference. If you use Claude Code, configure CLAUDE.md. If you use Gemini Code Assist, configure GEMINI.md. Many projects include config files for multiple tools so each team member can use their preferred editor.
PORTABILITY TIP
sync-instructions.sh
bash
# Maintain a single source of truth:
cp AI-INSTRUCTIONS.md CLAUDE.md
cp AI-INSTRUCTIONS.md .cursorrules
cp AI-INSTRUCTIONS.md AGENTS.md
SEE ALSO
Tool pages:
File references:
agentconfig.ing2026-03-18COMPARE(1)