# Deno v1.21.0 — Release & Upgrade Intelligence
- **Product:** Deno (https://deno.com)
- **Version:** v1.21.0
- **Released:** Apr 21, 2022
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/deno/updates/v1.21.0/

## Executive Summary (TL;DR)
Deno v1.21.0. Source highlight: View the full release blog post here.

## New Features
- feat(bench): update API, new console reporter (#14305)
- feat(cli/fmt): ignore .git folder when formatting files (#14138)
- feat(core): Add initial support for realms (#14019)
- feat(ext/net): `Deno.upgradeHttp` handles unix connections (#13987)
- feat(ext/web): add globalThis.reportError() (#13799)
- feat(repl): Don't type check when importing modules (#14112)

## Improvements
- perf(fmt/lint): incremental formatting and linting (#14314)
- perf(runtime): bypass tokio file and bump op buffer size to 64K (#14319)
- perf: move `Deno.writeTextFile` and like functions to Rust (#14221)

## Bug Fixes
- fix(cli/emit): Check JS roots with `// @ts-check` (#14090)
- fix(cli/tools/test): Prefix test module paths with `./` (#14301)
- fix(fmt): regression where some short if stmt headers being split on multiple
- fix(permissions): fallback to denied access if the permission prompt fails
- fix: `--watch` was losing items (#14317)
- fix: panic when trying to pledge permissions before restoring previous pledge