When you’re building or testing APIs, debugging can take forever. It usually means sending off requests, inspecting big JSON blobs, and repeating the same setup steps over and over. That’s where Postman shines. It’s not just for sending requests—it’s a powerful debugging tool. Three features in particular have made my workflow faster and less painful: Visualizer, Runner, and Scripts.
Visualizer: Making Large JSON Human-Friendly
APIs often return huge JSON responses. Scrolling through them in raw form isn’t just slow—it’s easy to miss important details.
Postman’s Visualizer solves that by letting you turn JSON into something you can scan at a glance. With a little HTML and JavaScript, you can render tables, charts, or highlights.
Here’s a quick example that shows IDs and names in a simple table:
// Tests tab in Postman
let template = `
<table border="1" style="border-collapse: collapse;">
<tr>
<th>ID</th>
<th>Name</th>
</tr>
{{#each response}}
<tr>
<td>{{id}}</td>
<td>{{name}}</td>
</tr>
{{/each}}
</table>
`;
pm.visualizer.set(template, {
response: pm.response.json()
});
Instead of scanning lines of JSON, I get a clear table view. Debugging large responses becomes a lot faster.
Runner: Automating Endpoints You Use Often
The Runner is another hidden gem. It lets you execute a collection of requests in sequence—great for when you need to seed data, reset your environment, or simulate a workflow.
Instead of manually running the same endpoints one by one, I can:
- Group them into a collection.
- Add scripts and variables for dynamic values.
- Run them all in one click.
This is especially helpful when debugging a bug that requires a specific setup. With Runner, I can recreate the environment in seconds.
Scripts: Automating the Small Stuff
Scripts in Postman let you run JavaScript before or after a request. They’re perfect for eliminating the copy-paste grind that slows debugging down.
Here’s a simple example that stores a user ID from a response:
let responseData = pm.response.json();
pm.environment.set("userId", responseData.id);
Postman is more than a request sender—it’s a debugging toolkit.
- Visualizer makes big JSON responses readable.
- Runner automates multi-step workflows.
- Scripts handle the small but repetitive tasks.
Together, these features turn tedious debugging into a faster, more reliable process. If you’re only using Postman to fire off single requests, it’s worth giving these other features a try. These tools might save you the same hours they’ve saved me.