Your recommended stack

3 areas to cover, based on what you told us

“We have little or no automated testing yet”

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1. Unit & Component Testing

Because you said: “We have little or no automated testing yet”

Buyer’s guide

VitestBest fitOpen source

Vite-native test runner with instant watch mode and a Jest-compatible API.

Why this fits you

Fastest watch-mode feedback of the JavaScript runners, by a wide margin on large repos.
Zero-config ESM and TypeScript — the single biggest source of Jest configuration pain simply disappears.

Main limitation

Assumes Vite. On a Webpack or Metro project the advantage largely evaporates.
Younger ecosystem; a handful of niche Jest plugins have no equivalent.

JestOpen source

The JavaScript testing incumbent: batteries included, snapshots, huge ecosystem.

Why this fits you

Everything in one dependency, with defaults that work for most projects on day one.
The largest ecosystem of matchers, reporters and framework presets in JavaScript.

Main limitation

Native ESM support remains awkward, and the Babel transform layer is a recurring configuration tax.
Noticeably slower than Vitest on large suites.

Testing LibraryOpen source

Query the DOM the way a user would, not the way the framework does.

Why this fits you

Tests survive refactors because they assert on user-visible output, not internals.
Accessible-role queries push teams towards accessible markup as a side effect.

Main limitation

Deliberately makes implementation-detail testing hard, which frustrates teams used to shallow rendering.
Async utilities and act() warnings are a common source of confusion.

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2. API & Contract Testing

Because you said: “We have little or no automated testing yet”

Buyer’s guide

PostmanBest fitfrom $9Free tier

The API platform most developers already have open: requests, collections, tests, mocks.

Why this fits you

Near-universal adoption
Covers design, mocking, testing, documentation and monitoring in one place.

Main limitation

Cloud-first sync raised real concerns for teams handling sensitive API credentials; the offline story has been repeatedly reduced.
Collections stored in the vendor cloud rather than your repo make code review and branching awkward.

Brunofrom $6Free tier

Git-native API client that stores collections as plain files in your repo.

Why this fits you

Collections live in Git, so they diff, branch and review like any other code.
Offline-first with no forced account — a genuine compliance advantage.

Main limitation

No built-in mock servers or monitoring; it is a client and runner, not a platform.
Younger project with a smaller ecosystem and fewer integrations.

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3. End-to-End & UI Test Automation

Because you said: “We have little or no automated testing yet”

Buyer’s guide

PlaywrightBest fitOpen source

Microsoft's cross-browser automation library with tracing and auto-waiting built in.

Why this fits you

Auto-waiting and web-first assertions remove most of the sleep() flake that plagues older tools.
The trace viewer — DOM snapshots, network, console and screenshots per step — is the best failure triage in the category.

Main limitation

No native mobile app support. Mobile means an emulated viewport, not a real device.
The API surface is large; teams without a conventions document end up with four ways to write the same locator.

Cypressfrom $75Free tier

Developer-first browser testing with an interactive runner developers actually enjoy.

Why this fits you

The interactive runner is the best onboarding experience in E2E testing; a new developer writes a passing test in minutes.
Excellent documentation and one of the largest plugin ecosystems.

Main limitation

Runs in the same event loop as your app, which historically meant no multi-tab, multi-origin or iframe-heavy testing without workarounds. Support has improved but the model still constrains you.
JavaScript and TypeScript only.

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