Prerequisites
Make sure the following conditions are met:
You are running your test on Chrome, Chromium, or Microsoft Edge
What Is Hot Reload?
Hot Reload lets you restart a test after the last successful step —without having to re-run everything from the beginning.
Instead of replaying the entire scenario, Thunders.ai resumes execution from the last failed step, so you can focus on debugging what matters.
Why Hot Reload?
Hot Reload is designed to dramatically speed up your iteration cycle:
Save time and money by avoiding starting from scratch and running only what’s necessary
Debug efficiently by testing your fix immediately.
Keep a single clean run, making analysis simpler and more consistent.
This feature is ideal when you’re fine-tuning scripts, adjusting selectors, or iterating on flows with long setups.
How to Use Hot Reload
1. Identify the failing step
Run your test as usual. When an error occurs, you’ll see the failing step highlighted.
2. Apply your fix
Update the step, or action causing the failure.
You can edit anything after the last successful step.
⚠️ Make sure you have not changed any execution settings (resolution, region, or any environment parameter) or green steps or persona.
⚠️ You must trigger Hot Reload within 5 minutes after the test finishes. Once this 5-minute window expires, the context is lost and a full execution is required. Each time you resume the run, a new 5-minute window automatically starts.
3. Click Resume / Hot Reload
A Resume button appears next to the failing step.
Click it to relaunch the execution from that point.
4. The test resumes after the last green step
Only the failed steps are executed again — the rest remains untouched.
5. Iterate as needed
You can trigger Hot Reload multiple times, as long as your execution context and settings remain valid. Each Hot Reload resets the 5-minute context window, giving you another opportunity to resume without a full rerun.
⚠️ Keep in mind that your total available execution time is capped at 60 minutes.
Troubleshooting / FAQ
Hot Reload button is not showing — why?
One of these conditions is likely true:
You’re on Firefox or Safari.
More than 5 minutes have passed since the failure.
Resolution, region, or environment settings were changed.
You modified a step that was already successful.
Can I modify any step before using Hot Reload?
You can modify any step after the last successful one.
Editing a green step forces a full test run.
Can I Hot Reload multiple times?
Yes — as long as:
You stay in the same execution context, and
You use Hot Reload within 5 minutes after each failure.
Does Hot Reload validate the full workflow?
No. It’s a speed-up tool for debugging.
For full validation or production confidence, run the entire test.
Why does the run stay the same after multiple Hot Reloads?
Because Hot Reload works inside one continuous run.
This keeps your debugging flow clean and avoids cluttering your test history.