cloudflare-r2

Status : Production Ready ✅ Last Updated : 2026-01-20 Dependencies : cloudflare-worker-base (for Worker setup) Latest Versions : wrangler@4.59.2, @cloudflare/workers-types@4.20260109.0, aws4fetch@1.0.20 Recent Updates (2025) : For files >100MB or resumable uploads. Use when: large files, browser uploads, parallelization needed. Limits : Parts 5MB-100MB, max 10,000 parts per upload. Don't use for files 100MB - Set CORS before browser uploads (use CLI format for wrangler) - Set expiry times on presigned URLs (1-24 hours) - Use head() when you only need metadata - Use conditional operations to prevent overwrites - Use custom domains for production (never r2.dev) - Shard writes across keys to avoid rate limits - Use include parameter with list() to get metadata - Implement retry logic with exponential backoff for 5xx errors - Never expose R2 access keys in client-side code - Never skip contentType (files download as binary) - Never delete in loops (use batch delete) - Never skip CORS for browser uploads - Never use multipart for small files ( 1000 keys in single call - Never skip presigned URL expiry (security risk) - Never use r2.dev domain for production (rate limited) - Never use presigned URLs with custom domains (use S3 domain) - Never write to same key at high frequency (causes 429) - Never use "Object Read & Write" tokens for wrangler (use "Admin Read & Write") - R2...