Short answer: Katalon is the right choice when you are building a QA practice and want one platform to hold all of it. Testmode is the right choice when you want tests without building a practice first.

Katalon is one of the broadest products in this category: four application types, three levels of coding, plus test management and execution infrastructure. Testmode does one thing. The decision is mostly about whether that breadth is coverage you need or surface area you maintain.

At a glance

	Katalon	Testmode
Test authoring	No-code recording, low-code, or full scripting	Plain English
Scope	Web, native mobile, API, Windows desktop	Web applications
Beyond execution	Test management, an execution cloud, production monitoring	Test execution
Setup	Install Studio, configure a project and suites	Point it at a URL
Escape hatch for hard cases	Drop into code	Rewrite the description
Cost model	Free tier, then priced by product and execution volume	Commercial product

Where Katalon is the better tool

You need desktop, mobile or API coverage. Windows desktop applications in particular are rare in this category and Katalon covers them. Testmode tests web applications.
You want the option to drop into code. Every codeless tool eventually meets a flow it cannot express. Katalon’s answer is that you write a script for that one case and stay in the same platform. That is a real safety net.
You want test management in the same place. Test cases, plans, execution history and traceability in one system matters to larger and regulated QA organisations.
You want a free way in. There is a free tier, which for a team proving the idea internally is worth a lot.

Where Testmode fits better

You do not want to adopt a platform. Katalon is something you roll out: install it, structure a project, decide conventions, train people. Testmode is a URL and a sentence. For a team with no automation today, that gap is most of the decision.
Recording is not how your team thinks. Katalon’s no-code path starts by performing the flow. Testmode’s starts by describing it — which works before the feature exists, and does not need the fiddly parts demonstrated.
Your application changes constantly. Recorded steps and scripted locators are both anchored to how the page is built today. Interpreting a described intent at run time degrades more gracefully through a redesign.
Nobody involved is a QA engineer. Katalon rewards expertise. If the person who knows what the software should do is in operations or product, a full quality platform is more tool than the job needs.

The honest summary

Katalon does far more than Testmode, and for an established QA team standardising on one platform across web, mobile, API and desktop, that breadth is exactly the point.

Testmode is for the case Katalon is poorly suited to: nobody to own a platform, no automation today, and a web application that needs checking before every release. Narrow, but reachable on the first afternoon.

Still comparing? Katalon alternatives covers the wider field. Or see every comparison.