# Vitest v4.1.3 — Release & Upgrade Intelligence
- **Product:** Vitest (https://vitest.dev)
- **Version:** v4.1.3
- **Released:** Apr 07, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/vitest/updates/v4.1.3/

## Executive Summary (TL;DR)
Vitest v4.1.3. Source highlight:    🚀 Experimental Features

## New Features
- Add `experimental.preParse` flag &nbsp;-&nbsp; by @sheremet-va in https://github.com/vitest-dev/vitest/issues/10070 <samp>(78273)</samp>
- Support `browser.locators.exact` option &nbsp;-&nbsp; by @sheremet-va in https://github.com/vitest-dev/vitest/issues/10013 <samp>(48799)</samp>
- Add `TestAttachment.bodyEncoding` &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9969 <samp>(89ca0)</samp>
- Support custom snapshot matcher &nbsp;-&nbsp; by @hi-ogawa, **Claude Sonnet 4.6** and **Codex** in https://github.com/vitest-dev/vitest/issues/9973 <samp>(59b0e)</samp>

## Bug Fixes
- Advance fake timers with `expect.poll` interval &nbsp;-&nbsp; by @hi-ogawa and **Claude Sonnet 4.6** in https://github.com/vitest-dev/vitest/issues/10022 <samp>(3f5bf)</samp>
- Add `@vitest/coverage-v8` and `@vitest/coverage-istanbul` as optional dependency &nbsp;-&nbsp; by @alan-agius4 in https://github.com/vitest-dev/vitest/issues/10025 <samp>(146d4)</samp>
- Fix `defineHelper` for webkit async stack trace + update playwright 1.59.0 &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/10036 <samp>(5a5fa)</samp>
- Fix suite hook throwing errors for unused auto test-scoped fixture &nbsp;-&nbsp; by @hi-ogawa and **Claude Sonnet 4.6** in https://github.com/vitest-dev/vitest/issues/10035 <samp>(39865)</samp>
- Remove `JestExtendError.context` from verbose error reporting &nbsp;-&nbsp; by @hi-ogawa in https://github.com/vitest-dev/vitest/issues/9983 <samp>(66751)</samp>
- Don't leak "runner" types &nbsp;-&nbsp; by @sheremet-va in https://github.com/vitest-dev/vitest/issues/10004 <samp>(ec204)</samp>