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Testing · head to head

Split vs Vitest

Split logo

Split

Testing

Feature flags tied to a metrics pipeline that attributes production impact to each release, now Harness FME

From
On request
Rated
-
Full reviewWebsite
Vitest logo

Vitest

Testing

Fast unit test framework powered by Vite

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Vitest has a free tier, so it costs nothing to try first.
  • Each has a real cost: Split split is now a module of the Harness platform and split.io redirects to harness.io, so buying it means entering a Harness commercial relationship rather than a standalone flag vendor contract.; Vitest assumes Vite: projects on webpack or other bundlers lose the main advantage
  • They diverge on capability: Split covers Feature flags with targeting, Vitest covers Shares Vite config.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Split and Vitest actually diverge.

Attributes where Split and Vitest differ
AttributeSplitVitest
Starting priceOn requestFree
Pricing modelquoteOpen source, no licence fee
Free tierNoYes
PlatformsWeb, API, iOS, Android, Java, Node.js, Python, Go, .NETLinux, macOS, Windows

Identical on both: user rating (Not yet rated), category (Testing).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Split

  • Feature flags with targeting
  • Metrics impact engine
  • Guardrail metrics
  • Statistical significance testing
  • Event ingestion
  • SDKs and streaming updates
  • Audit and approvals
  • Harness platform integration

Only in Vitest

  • Shares Vite config
  • Jest-compatible API
  • Fast watch mode
  • ESM and TypeScript native

What people use each for

The jobs each tool is most often brought in to do.

Split

  • A product organisation that wants every release measured against conversion and latency by default, not only deliberate experimentsnot Vitest
  • Running A/B tests with real statistical significance rather than comparing two dashboard linesnot Vitest
  • Catching a regression at five per cent rollout because a guardrail metric fires before the change reaches everyonenot Vitest
  • A team already committed to Harness for CI and CD that wants flags in the same platform and contractnot Vitest

Vitest

  • Unit testing an application already built with Vite, without a second build confignot Split
  • Migrating from Jest for faster watch-mode feedbacknot Split
  • Testing TypeScript and ESM code without transform configurationnot Split

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Split

  • Split is now a module of the Harness platform and split.io redirects to harness.io, so buying it means entering a Harness commercial relationship rather than a standalone flag vendor contract.
  • Harness no longer publishes per-module prices, so an organisation that wants only feature management cannot get a list price and must negotiate a module out of a platform bundle.
  • The measurement engine needs traffic volume to reach significance, so a product with modest usage gets flags with an experimentation layer it will rarely be able to conclude anything from.
  • Metric attribution depends on correctly instrumented events flowing into Split, which is an integration project in its own right; without it you have paid for an experimentation platform and are using it as a flag switch.
  • As part of a larger DevOps suite the roadmap now competes with CI, CD, security and cloud cost modules for attention, so feature management is no longer the company’s single focus the way it was as an independent product.

Vitest

  • Assumes Vite: projects on webpack or other bundlers lose the main advantage
  • Younger than Jest, so some plugins and matchers in the Jest ecosystem have no equivalent
  • Jest compatibility is close but not exact, and unusual Jest configurations still need work to port

Pricing, plan by plan

Split

On request
  • Harness FreeFree
    • Harness Open Source and community support
    • Intended for individuals and small teams
    • Feature management capability limited at this tier
  • Harness Essentials$undefined/year
    • Bundled DevOps modules including CI, CD, IaC and security testing
    • Standard support
    • Pricing requires contacting sales
  • Harness Enterprise$undefined/year
    • Mix and match from 15 or more modules including Feature Management and Experimentation
    • Premier support with a dedicated account manager
    • Higher pipeline concurrency and organisation limits

Vitest

Free
  • VitestFree
    • Full functionality
    • Unlimited tests
    • Community support

Which should you pick?

Choose Split if

  • You need feature flags with targeting.
  • You work on Web, API, iOS, Android, Java, Node.js, Python, Go, .NET.
  • You also want metrics impact engine.
Split review

Choose Vitest if

  • You need shares vite config.
  • You want to start without paying.
  • You work on Linux, macOS, Windows.
  • You also want jest-compatible api.
Vitest review

Questions people ask

Is Split or Vitest better?
Neither clearly leads. Split starts at On request and Vitest at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Split or Vitest?
Vitest has a free tier; the other does not. Paid plans start at On request for Split and Free for Vitest.
Does Split or Vitest run on more platforms?
Split runs on Web, API, iOS, Android, Java, Node.js, Python, Go, .NET. Vitest runs on Linux, macOS, Windows.
Can I use Vitest for free?
Yes. Vitest has a free tier, so you can try it without paying. Split starts at On request.
What is Split best used for?
Split is most often used for a product organisation that wants every release measured against conversion and latency by default, not only deliberate experiments, running a/b tests with real statistical significance rather than comparing two dashboard lines, catching a regression at five per cent rollout because a guardrail metric fires before the change reaches everyone, a team already committed to harness for ci and cd that wants flags in the same platform and contract. Of those, a product organisation that wants every release measured against conversion and latency by default, not only deliberate experiments and running a/b tests with real statistical significance rather than comparing two dashboard lines are not what Vitest is typically brought in for.
What can Split do that Vitest cannot?
Split covers Feature flags with targeting, Metrics impact engine, Guardrail metrics, Statistical significance testing. Vitest covers Shares Vite config, Jest-compatible API, Fast watch mode, ESM and TypeScript native.

Answered from the vendors’ own pages

Split: Is Split still called Split?

It is now sold as Harness Feature Management and Experimentation after the Harness acquisition, and split.io redirects to harness.io.

Vitest: Is Vitest free?

Yes, open source under the MIT licence.

Split: Can I buy just feature flags?

Not from a price list. Harness publishes bundle tiers and directs single-module buyers to sales.

Vitest: Is Vitest compatible with Jest?

The API is deliberately Jest-compatible and most migrations are mechanical, though unusual configurations and some ecosystem plugins need attention.

Split: What does it do that a plain flag service does not?

It attributes changes in your product metrics to specific flags with statistical significance testing and alerts on guardrail metrics.

Vitest: Do I need Vite to use Vitest?

It works without a Vite app but the main benefit — sharing one config and transform pipeline — only applies if you are already using Vite.

Split: Do we need a lot of traffic?

Yes. Statistical tests need volume to conclude, so low-traffic products get limited value from the measurement layer.

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