Profiling with Debug Toolbar
Measure query count and timing.
Profiling with Debug Toolbar is a free Django Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Django Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Measure, Do Not Guess
The Django Debug Toolbar shows exactly how many queries a page runs, so you optimize with facts instead of hunches. 🔍
Install It
You add it with pip, just like any package. It is a development tool, so it never ships to production.
pip install django-debug-toolbarRegister the App
Add it to INSTALLED_APPS so Django loads its panels and knows the toolbar exists.
INSTALLED_APPS += ['debug_toolbar']Add the Middleware
Its middleware injects the panel into HTML responses, so it sits near the top of your middleware list.
MIDDLEWARE += [
'debug_toolbar.middleware.DebugToolbarMiddleware']Allow Your IP
The toolbar only appears for IPs in INTERNAL_IPS, which keeps it visible to you but hidden from real visitors.
INTERNAL_IPS = ['127.0.0.1']The SQL Panel
The star panel is SQL. It lists every query a page ran, with its timing, right beside the rendered output.
Spot the Query Count
A surprisingly high query count is the classic fingerprint of N+1. The toolbar makes that number impossible to miss.
Find Duplicates
It even flags duplicate queries, the near-identical ones a loop fires over and over, pointing straight at the problem.
Confirm Your Fix
After adding select_related or prefetch_related, reload and watch the count drop. That is your proof the fix worked.
Read the Timings
Slow pages are not always about count. The toolbar shows time per query, so you can chase the truly expensive ones.
Keep It Dev-Only
Wrap toolbar settings behind your DEBUG flag. It can leak internals and slow pages, so production must never see it.
Quick Check
One last check on profiling habits.
Recap
The Debug Toolbar counts and times queries so you can spot N+1 and confirm fixes. Install it, allow your IP, and keep it dev-only. ✅
Frequently asked questions
Is the “Profiling with Debug Toolbar” lesson free?
Yes — the full text of “Profiling with Debug Toolbar” is free to read here on the web, and the Django Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Django Academy course, upgrade to CoddyKit PRO.
What will I learn in “Profiling with Debug Toolbar”?
Measure query count and timing. You practise Django Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Django Academy?
No prior experience is required. Django Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Profiling with Debug Toolbar” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Django Academy lesson?
Yes. Every Django Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Spotting the N+1 Problem
- select_related for Foreign Keys
- prefetch_related for M2M
- Profiling with Debug Toolbar