This page documents error codes returned by R2 when using the Workers API or the S3-compatible API , along with recommended fixes to help with troubleshooting.
For the Workers API , R2 operations throw exceptions that you can catch. The error code is included at the end of the message property:
await env . MY_BUCKET . put ( "my-key" , data , { customMetadata : largeMetadata } ) ;
console . error ( error . message ) ;
// "put: Your metadata headers exceed the maximum allowed metadata size. (10012)"
For the S3-compatible API , errors are returned as XML in the response body:
<? xml version = "1.0" encoding = "UTF-8" ?>
< Message > The specified key does not exist. </ Message >
Authentication and authorization errors Error Code S3 Code HTTP Status Details Recommended Fix 10002 Unauthorized 401 Missing or invalid authentication credentials. Verify your API token or access key credentials are correct and have not expired. 10003 AccessDenied 403 Insufficient permissions for the requested operation. Check that your API token has the required permissions for the bucket and operation. 10018 ExpiredRequest 400 Presigned URL or request signature has expired. Regenerate the presigned URL or signature. 10035 SignatureDoesNotMatch 403 Request signature does not match calculated signature. Verify your secret key and signing algorithm. Check for URL encoding issues. 10042 NotEntitled 403 Account not entitled to this feature. Ensure your account has an R2 subscription .
Error Code S3 Code HTTP Status Details Recommended Fix 10005 InvalidBucketName 400 Bucket name does not meet naming requirements. Bucket names must be 3-63 chars, lowercase alphanumeric and hyphens, start/end with alphanumeric. 10006 NoSuchBucket 404 The specified bucket does not exist. Verify the bucket name is correct and the bucket exists in your account. 10008 BucketNotEmpty 409 Cannot delete bucket that contains objects. Delete all objects in the bucket before deleting the bucket. 10009 TooManyBuckets 400 Account bucket limit exceeded (default: 1,000,000 buckets). Request a limit increase via the Limits Increase Request Form ↗ . 10073 BucketConflict 409 Bucket name already exists. Choose a different bucket name. Bucket names must be unique within your account.
Error Code S3 Code HTTP Status Details Recommended Fix 10007 NoSuchKey 404 The specified object key does not exist. For the Workers API , get() and head() return null instead of throwing. Verify the object key is correct and the object has not been deleted. 10020 InvalidObjectName 400 Object key contains invalid characters or is too long. Use valid UTF-8 characters. Maximum key length is 1024 bytes. 100100 EntityTooLarge 400 Object exceeds maximum size (5 GiB for single upload, 5 TiB for multipart). Use multipart upload for objects larger than 5 GiB. Maximum object size is 5 TiB. 10012 MetadataTooLarge 400 Custom metadata exceeds the 8,192 byte limit. Reduce custom metadata size. Maximum is 8,192 bytes total for all custom metadata. 10069 ObjectLockedByBucketPolicy 403 Object is protected by a bucket lock rule and cannot be modified or deleted. Wait for the retention period to expire. Refer to bucket locks .
Upload and request errors Error Code S3 Code HTTP Status Details Recommended Fix 10033 MissingContentLength 411 Content-Length header required but missing.Include the Content-Length header in PUT/POST requests. 10013 IncompleteBody 400 Request body terminated before expected Content-Length. Ensure the full request body is sent. Check for network interruptions or client timeouts. 10014 InvalidDigest 400 Checksum header format is malformed. Ensure checksums are properly encoded (base64 for SHA/CRC checksums). 10037 BadDigest 400 Provided checksum does not match the uploaded content. Verify data integrity and retry the upload. 10039 InvalidRange 416 Requested byte range is not satisfiable. Ensure the range start is less than object size. Check Range header format. 10031 PreconditionFailed 412 Conditional headers (If-Match, If-Unmodified-Since, etc.) were not satisfied. Object's ETag or modification time does not match your condition. Refetch and retry. Refer to conditional operations .
Error Code S3 Code HTTP Status Details Recommended Fix 10011 EntityTooSmall 400 Multipart part is below minimum size (5 MiB), except for the last part. Ensure each part (except the last) is at least 5 MiB. 10024 NoSuchUpload 404 Multipart upload does not exist or was aborted. Verify the uploadId is correct. By default, incomplete multipart uploads expire after 7 days. Refer to object lifecycles . 10025 InvalidPart 400 One or more parts could not be found when completing the upload. Verify each part was uploaded successfully and use the exact ETag returned from UploadPart. 10048 InvalidPart 400 All non-trailing parts must have the same size. Ensure all parts except the last have identical sizes. R2 requires uniform part sizes for multipart uploads.
Error Code S3 Code HTTP Status Details Recommended Fix 10001 InternalError 500 An internal error occurred. Retry the request. If persistent, check Cloudflare Status ↗ or contact support. 10043 ServiceUnavailable 503 Service is temporarily unavailable. Retry with exponential backoff. Check Cloudflare Status ↗ . 10054 ClientDisconnect 400 Client disconnected before request completed. Check network connectivity and retry. 10058 TooManyRequests 429 Rate limit exceeded. Often caused by multiple concurrent requests to the same object key (limit: 1 write/second per key). Check if multiple clients are accessing the same object key. See R2 limits .
