Logging Open WebUI

Control what Open WebUI logs, where it goes, and how it's formatted, from quick debugging to production log pipelines.

Open WebUI has two logging surfaces: the browser console for frontend debugging and the Python backend for server-side events. Most configuration happens on the backend, where you can adjust verbosity with a single environment variable or switch to structured JSON output for log aggregators like Loki, Datadog, or CloudWatch.

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Frontend Logging

The frontend uses standard browser console.log() calls. Open your browser's developer tools (F12 or Cmd+Option+I on macOS), navigate to the Console tab, and you'll see informational messages, warnings, and errors from the client application.

Browser-specific documentation:

• Chrome/Chromium DevTools
• Firefox Developer Tools
• Safari Developer Tools

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Backend Logging

The backend uses Python's built-in logging module. By default, logs are written to stdout at the INFO level, making them visible in your terminal or container logs.

Log Levels

Level	Value	When to use
CRITICAL	50	Catastrophic failures; the application may terminate
ERROR	40	Failed operations; the application continues but something broke
WARNING	30	Unexpected situations worth investigating: deprecations, resource pressure
INFO	20	Normal operation flow: startup, key events, request handling (default)
DEBUG	10	Detailed diagnostic output: function calls, variable values, execution steps

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Setting the Global Log Level

Set GLOBAL_LOG_LEVEL to change verbosity for the entire backend. This configures the root Python logger via logging.basicConfig(force=True), affecting all Open WebUI loggers and most third-party libraries.

Docker:

--env GLOBAL_LOG_LEVEL="DEBUG"

Docker Compose:

environment:
  - GLOBAL_LOG_LEVEL=DEBUG

tip

Use DEBUG for development and troubleshooting. For production, stick with INFO or WARNING to keep log volume manageable.

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Structured JSON Logging

For production environments using log aggregators, set LOG_FORMAT=json to switch all stdout output to single-line JSON objects.

Docker:

--env LOG_FORMAT="json"

Docker Compose:

environment:
  - LOG_FORMAT=json

JSON fields:

Field	Description
ts	ISO 8601 timestamp
level	Log level (debug, info, warn, error, fatal)
msg	Log message
caller	Source location (module:function:line)
extra	Additional context data (if any)
error	Error details (if applicable)
stacktrace	Stack trace (if applicable)

Example output:

{"ts": "2026-02-22T20:14:53.386+00:00", "level": "info", "msg": "GLOBAL_LOG_LEVEL: INFO", "caller": "open_webui.env"}
{"ts": "2026-02-22T20:15:02.245+00:00", "level": "info", "msg": "Context impl SQLiteImpl.", "caller": "alembic.runtime.migration"}

note

• Default behavior (no LOG_FORMAT set) is unchanged: plain-text output
• The ASCII banner is suppressed when LOG_FORMAT=json to keep the log stream parseable
• JSON logging covers both early startup logs (stdlib logging) and runtime logs (Loguru)