Lightweight performance devbar for Django. Shows DB query count, query duration, application time, and detects similar and duplicate queries with visual severity indicators.

Normal operation – showing query count, duration, and application time:

Similar and duplicate queries detected – severity indicators and details shown:

[optional] Browser extension (Chrome and Firefox) — showing detailed metrics in DevTools panel:

While Django Debug Toolbar is a proven tool trusted by countless projects, django-devbar explores a different approach to development debugging:

• Minimal setup — just add middleware, nothing else required
• Browser DevTools integration — extension panel works with any response type, including JSON
• Zero extra dependencies — only requires Django
• Lower overhead — no extra requests to debug endpoints
• Non-intrusive — HTML bar is optional; works via headers and DevTools panel alone

# Using uv (recommended)
uv add --dev django-devbar

# Or using pip
pip install django-devbar

Add to your middleware early. For example:

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    # ...
]

if DEBUG:
    idx = MIDDLEWARE.index("django.middleware.security.SecurityMiddleware")
    MIDDLEWARE.insert(idx + 1, "django_devbar.DevBarMiddleware")

This keeps the middleware active only in development and avoids import errors if the package isn't installed in production.

All settings are optional. Configure via a DEVBAR dict in your Django settings:

DEVBAR = {
    "POSITION": "bottom-right",  # bottom-right (default), bottom-left, top-right, top-left
    "SHOW_BAR": None,  # follows DEBUG; set True/False to override
    "ENABLE_DEVTOOLS_DATA": None,  # follows DEBUG; set True/False to override
    "DEVTOOLS_HEADER_MAX_BYTES": 6144,  # max bytes for DevBar-Data header payload
    "DEVTOOLS_MAX_QUERIES": None,  # optional hard cap for q/dup entries sent to DevTools
}

Django DevBar adds HTTP response headers with performance metrics:

• Server-Timing (always present) – Standard HTTP header with database, application, and total time metrics. Visible in browser DevTools Network tab under Timing.

An additional header is included by default in DEBUG mode:

• DevBar-Data - JSON header with comprehensive metrics including similar and duplicate query details
  • Query-level flags are embedded in q entries (dup and sim)
  • Payload is automatically truncated to fit DEVTOOLS_HEADER_MAX_BYTES
  • When truncated, response includes metadata keys: tr, q_total, q_sent

This is useful for:

• API endpoints where the HTML overlay can't be displayed
• Automated testing to assert performance metrics (e.g., fail CI if query count exceeds a limit)
• Browser extensions that need detailed duplicate query information

Server-Timing: db;dur=87.50, app;dur=41.30, total;dur=128.80

View Django DevBar metrics directly in browser DevTools. Install from Chrome Web Store or Firefox Add-ons.

See browser-extension/README.md for more details.