HTTP status codes are an essential part of web communication, indicating the result of a client’s request to a server. Here’s an expanded list of status codes, their meanings, and how to use them in a Rails API.

---

1xx: Informational

100

code - 100
status - :continue
Info - Continue

# This is typically handled by the server automatically

—

101

code - 101
status - :switching_protocols
Info - Switching Protocols

# This is typically handled by the server automatically

—

102

code - 102
status - :processing
Info - Processing

# This is typically used in WebDAV

---

2xx: Success

200

code - 200
status - :ok
Info - OK

render json: { message: 'Success' }, status: :ok

—

201

code - 201
status - :created
Info - Created

render json: { message: 'Resource created' }, status: :created

—

202

code - 202
status - :accepted
Info - Accepted

render json: { message: 'Request accepted for processing' }, status: :accepted

—

203

code - 203
status - :non_authoritative_information
Info - Non-Authoritative Information

render json: { message: 'Information from a third-party source' }, status: :non_authoritative_information

—

204

code - 204
status - :no_content
Info - No Content

head :no_content

—

205

code - 205
status - :reset_content
Info - Reset Content

head :reset_content

—

206

code - 206
status - :partial_content
Info - Partial Content

render json: { partial_data: data }, status: :partial_content

---

3xx: Redirection

300

code - 300
status - :multiple_choices
Info - Multiple Choices

render json: { choices: options }, status: :multiple_choices

—

301

code - 301
status - :moved_permanently
Info - Moved Permanently

redirect_to new_url, status: :moved_permanently

—

302

code - 302
status - :found
Info - Found

redirect_to other_url, status: :found

—

303

code - 303
status - :see_other
Info - See Other

redirect_to other_url, status: :see_other

—

304

code - 304
status - :not_modified
Info - Not Modified

head :not_modified

—

307

code - 307
status - :temporary_redirect
Info - Temporary Redirect

redirect_to temp_url, status: :temporary_redirect

—

308

code - 308
status - :permanent_redirect
Info - Permanent Redirect

redirect_to new_permanent_url, status: :permanent_redirect

---

4xx: Client Errors

400

code - 400
status - :bad_request
Info - Bad Request

render json: { error: 'Invalid parameters' }, status: :bad_request

—

401

code - 401
status - :unauthorized
Info - Unauthorized

render json: { error: 'Authentication required' }, status: :unauthorized

—

402

code - 402
status - :payment_required
Info - Payment Required

render json: { error: 'Payment required to access this resource' }, status: :payment_required

—

403

code - 403
status - :forbidden
Info - Forbidden

render json: { error: 'Access denied' }, status: :forbidden

—

404

code - 404
status - :not_found
Info - Not Found

render json: { error: 'Resource not found' }, status: :not_found

—

405

code - 405
status - :method_not_allowed
Info - Method Not Allowed

render json: { error: 'Method not allowed' }, status: :method_not_allowed

—

406

code - 406
status - :not_acceptable
Info - Not Acceptable

render json: { error: 'Not acceptable' }, status: :not_acceptable

—

409

code - 409
status - :conflict
Info - Conflict

render json: { error: 'Resource conflict' }, status: :conflict

—

410

code - 410
status - :gone
Info - Gone

render json: { error: 'Resource no longer available' }, status: :gone

—

422

code - 422
status - :unprocessable_entity
Info - Unprocessable Entity

render json: { errors: resource.errors }, status: :unprocessable_entity

—

429

code - 429
status - :too_many_requests
Info - Too Many Requests

render json: { error: 'Rate limit exceeded' }, status: :too_many_requests

---

5xx: Server Errors

500

code - 500
status - :internal_server_error
Info - Internal Server Error

render json: { error: 'Internal Server Error' }, status: :internal_server_error

—

501

code - 501
status - :not_implemented
Info - Not Implemented

render json: { error: 'Functionality not implemented' }, status: :not_implemented

—

502

code - 502
status - :bad_gateway
Info - Bad Gateway

render json: { error: 'Bad Gateway' }, status: :bad_gateway

—

503

code - 503
status - :service_unavailable
Info - Service Unavailable

render json: { error: 'Service Unavailable' }, status: :service_unavailable

—

504

code - 504
status - :gateway_timeout
Info - Gateway Timeout

render json: { error: 'Gateway Timeout' }, status: :gateway_timeout

—

507

code - 507
status - :insufficient_storage
Info - Insufficient Storage

render json: { error: 'Insufficient storage' }, status: :insufficient_storage

—

511

code - 511
status - :network_authentication_required
Info - Network Authentication Required

render json: { error: 'Network authentication required' }, status: :network_authentication_required

---

Note that while Rails provides symbols for many status codes, you can always use the numerical code directly if a symbol is not available:

render json: { message: 'Custom status' }, status: 418

When building APIs, using appropriate status codes helps clients understand and handle responses correctly, leading to more robust and maintainable applications. It’s important to choose the most specific and appropriate status code for each situation to provide clear and accurate information to API consumers.