⚠️ Breaking Change
Impact Score: 7/10
Deno v1.20.1 — Release Notes & Engineering Impact
Source available — automated, not human-reviewed
Component: deno · Channel: stable. Automated analysis, not a compatibility certification. How this works.
Analysis updated: 2026-11-01.
Breaking-change evidence from the source
- BREAKING: don't inherit permissions by default (#13668)
⚡ Executive Summary (TL;DR)
Deno v1.20.1. Source highlight: BREAKING: don't inherit permissions by default (#13668)
Who Does This Impact? (Role-Based Analysis)
💻 Software Engineers & Devs
Check the source notes against the package and APIs you use before upgrading.
📊 Product & Engineering Leads
Use the documented changes to assess relevance to your product; release frequency alone is not a quality measure.
⚙️ DevOps & Security
Verify the target version, runtime requirements and rollback procedure in the official documentation.
⚠️ Breaking Changes & Deprecations (1)
- - BREAKING: don't inherit permissions by default (#13668)
✨ New Features & Capabilities (6)
- feat(cli): support data url (#13667)
- feat(cli): update to TypeScript 4.6.2 (#13474)
- feat(compat): CJS/ESM interoperability (#13553)
- feat(core): Event loop middlewares for Extensions (#13816)
- feat(core): codegen ops (#13861)
- feat(ext/crypto): AES-GCM support for 128bit IVs (#13805)
⚡ Performance & Enhancements (4)
- perf(web): Optimize `TextDecoder` by adding a new `U16String` type (#13923)
- perf(web): optimize Blob.text and Blob.arrayBuffer (#13981)
- perf(web): use DOMString for BlobParts (#13979)
- perf: opt-level-3 all of ext (#13940)
🔧 Bug Fixes & Patches (6)
- feat(ext/http): auto-compression of fixed response bodies (#13769)
- fix(compat): cjs/esm interop for dynamic imports (#13792)
- fix(core): Don't override structured clone error messages from V8 (#13942)
- fix(core): nuke Deno.core.ops pre-snapshot (#13970)
- fix(ext/crypto): handle JWK import with "use" (#13912)
- fix(ext/crypto): use EcKeyImportParams dictionary (#13894)
📄 View Raw Release Notes (Original Developer Log)
### 1.20.1 / 2022.03.16
- BREAKING: don't inherit permissions by default (#13668)
- feat(cli): support data url (#13667)
- feat(cli): update to TypeScript 4.6.2 (#13474)
- feat(compat): CJS/ESM interoperability (#13553)
- feat(core): Event loop middlewares for Extensions (#13816)
- feat(core): codegen ops (#13861)
- feat(ext/crypto): AES-GCM support for 128bit IVs (#13805)
- feat(ext/fetch): Allow Response status 101 (#13969)
- feat(ext/http): auto-compression of fixed response bodies (#13769)
- feat(ext/net): Use socket2 crate to create TcpListener (#13808)
- feat(ext/net): support cert, key options in listenTls (#13740)
- feat(ext/web): Add `AbortSignal.timeout()` (#13687)
- feat(net): add Deno.UnixConn interface (#13787)
- feat(ops): custom arity (#13949)
- feat(ops): optional OpState (#13954)
- feat(unstable): Add Deno.upgradeHttp API (#13618)
- feat: "deno bench" subcommand (#13713)
- feat: "deno task" subcommand (#13725)
- feat: Add Deno.TcpConn class, change return type from Deno.connect (#13714)
- feat: allow specification of import map in config file (#13739)
- feat: deno test --trace-ops (#13770)
- fix(compat): cjs/esm interop for dynamic imports (#13792)
- fix(core): Don't override structured clone error messages from V8 (#13942)
- fix(core): nuke Deno.core.ops pre-snapshot (#13970)
- fix(ext/crypto): handle JWK import with "use" (#13912)
- fix(ext/crypto): use EcKeyImportParams dictionary (#13894)
- fix(ext/http): drop content-length header on compression (#13866)
- fix(info): print deno info paths with unescaped backslashes on windows (#13847)
- fix(test): skip typechecking for blocks inside HTML comments (#13889)
- fix: shell completion hints (#13876)
- fix: upgrade reqwest to 0.11.10 (#13951)
- perf(web): Optimize `TextDecoder` by adding a new `U16String` type (#13923)
- perf(web): optimize Blob.text and Blob.arrayBuffer (#13981)
- perf(web): use DOMString for BlobParts (#13979)
- perf: opt-level-3 all of ext (#13940)
Note 1.20.0 was dead on arrival, see https://github.com/denoland/deno/pull/13993