az webapp log startup

This command group is in preview and under development. Reference and support levels: https://aka.ms/CLI_refstatus

View web app container startup logs.

View startup logs written during container initialization for Linux web apps. Use when a container fails to start, crashes on cold start, times out waiting for a port, or returns HTTP 502/503 errors after deployment. These logs contain platform lifecycle events and container stdout/stderr output.

Commands

Name	Description	Type	Status
az webapp log startup list	List all container startup log files for a web app.	Core	Preview
az webapp log startup show	Show the content of a container startup log.	Core	Preview

az webapp log startup list

Preview

Command group 'webapp log startup' is in preview and under development. Reference and support levels: https://aka.ms/CLI_refstatus

List all container startup log files for a web app.

az webapp log startup list --name
                           --resource-group
                           [--instance]
                           [--outcome {failure, success}]
                           [--slot]

Examples

List all startup log files

az webapp log startup list --name MyWebApp --resource-group MyResourceGroup

List only failure logs

az webapp log startup list --name MyWebApp --resource-group MyResourceGroup --outcome failure

Required Parameters

--name -n

Name of the web app. If left unspecified, a name will be randomly generated. You can configure the default using az configure --defaults web=<name>.

--resource-group -g

Name of resource group. You can configure the default group using az configure --defaults group=<name>.

Optional Parameters

The following parameters are optional, but depending on the context, one or more might become required for the command to execute successfully.

--instance

Filter by worker instance name.

--outcome

Filter by startup outcome.

Property	Value
Accepted values:	failure, success

--slot -s

The name of the slot. Default to the production slot if not specified.

Global Parameters

--debug

Increase logging verbosity to show all debug logs.

Property	Value
Default value:	False

--help -h

Show this help message and exit.

--only-show-errors

Only show errors, suppressing warnings.

Property	Value
Default value:	False

--output -o

Output format.

Property	Value
Default value:	json
Accepted values:	json, jsonc, none, table, tsv, yaml, yamlc

--query

JMESPath query string. See http://jmespath.org/ for more information and examples.

--subscription

Name or ID of subscription. You can configure the default subscription using az account set -s NAME_OR_ID.

--verbose

Increase logging verbosity. Use --debug for full debug logs.

Property	Value
Default value:	False

az webapp log startup show

Preview

Command group 'webapp log startup' is in preview and under development. Reference and support levels: https://aka.ms/CLI_refstatus

Show the content of a container startup log.

By default, shows the most recent startup log (preferring a failure log when one exists for the latest date). Use --filename to view a specific log file, or --instance to scope the latest-log lookup to a specific worker. --filename and --instance are mutually exclusive.

az webapp log startup show --name
                           --resource-group
                           [--filename]
                           [--instance]
                           [--slot]

Examples

Show the latest startup log (prefers failures)

az webapp log startup show --name MyWebApp --resource-group MyResourceGroup

Show a specific startup log file

az webapp log startup show --name MyWebApp --resource-group MyResourceGroup --filename 2026_04_13_lw0sdlwk000002_failure.log

Show the latest startup log for a specific worker instance

az webapp log startup show --name MyWebApp --resource-group MyResourceGroup --instance lw0sdlwk000002

Required Parameters

--name -n

Name of the web app. If left unspecified, a name will be randomly generated. You can configure the default using az configure --defaults web=<name>.

--resource-group -g

Name of resource group. You can configure the default group using az configure --defaults group=<name>.

Optional Parameters

The following parameters are optional, but depending on the context, one or more might become required for the command to execute successfully.

--filename -f

Name of a specific startup log file to display. If not specified, shows the latest log (preferring failures).

--instance

Filter by worker instance name.

--slot -s

The name of the slot. Default to the production slot if not specified.

Global Parameters

--debug

Increase logging verbosity to show all debug logs.

Property	Value
Default value:	False

--help -h

Show this help message and exit.

--only-show-errors

Only show errors, suppressing warnings.

Property	Value
Default value:	False

--output -o

Output format.

Property	Value
Default value:	json
Accepted values:	json, jsonc, none, table, tsv, yaml, yamlc

--query

JMESPath query string. See http://jmespath.org/ for more information and examples.

--subscription

Name or ID of subscription. You can configure the default subscription using az account set -s NAME_OR_ID.

--verbose

Increase logging verbosity. Use --debug for full debug logs.

Property	Value
Default value:	False