# Vitest v5.1.0-beta.1 — Release & Upgrade Intelligence
- **Product:** Vitest (https://vitest.dev)
- **Version:** v5.1.0-beta.1
- **Released:** Oct 19, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/vitest/updates/v5.1.0-beta.1/
## Executive Summary (TL;DR)
Vitest v5.1.0-beta.1. Source highlight: 🚀 Features
## New Features
- Add `--last-failed` to run only failed tests - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11558 (82f63)
- Support `Temporal.Instant` and `Temporal.ZonedDateTime` in `vi.setSystemTime()` - by @Prajwal2246, **Prajwal2246**, **Claude Opus 5.5**, **Hiroshi Ogawa** and **Codex (GPT-6)** in https://github.com/vitest-dev/vitest/issues/11321 (f150f)
- Introduce `--since-last-run` flag - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11516 (08bd9)
- Expose per-retry/repeat attempt result - by @hi-ogawa, **Hiroshi Ogawa**, **Codex (GPT-6)** and **Claude Opus 5.5** in https://github.com/vitest-dev/vitest/issues/11232 (21be4)
- Support fake timers for `node:timers` and `node:timers/promise` - by @hi-ogawa, **Hiroshi Ogawa**, **OpenCode** and **Codex (GPT-6)** in https://github.com/vitest-dev/vitest/issues/10899 (fbe97)
- Mock modules through an import map - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11534 (707f8)
## Improvements
- Reuse fsModuleCache in static collection - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11622 (1766c)
- **browser**: Map only first frame for trace locations - by @hi-ogawa, **Hiroshi Ogawa** and **Claude Opus 5.5** in https://github.com/vitest-dev/vitest/issues/11613 (a967d)
## Bug Fixes
- Rerun setup files after `--changed` filtering - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11621 (3a39c)
- Return the mock to concurrent imports - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11623 (1453b)
- Don't fail on console log pending at teardown - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11619 (a60b8)
- Reference chai types in every d.ts chunk - by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11618 (fb150)
- Change default port to 23315 - by @hi-ogawa, **Hiroshi Ogawa** and **Claude Opus 5.5** in https://github.com/vitest-dev/vitest/issues/11640 (a2ec4)
- Advance fake timers in actions and expect.element - by @julienw, **Hiroshi Ogawa** and **Claude Opus 5.5** in https://github.com/vitest-dev/vitest/issues/11242 (68190)