What is the TypeScript 1.2 release date
TypeScript 1.2 reached general availability on September 21, 2016. This status clarifier explains what that means for users, which features shipped in that release, and how to verify you are on the correct version. It is written for developers, teams, and platform owners who need an answer-first explanation they can rely on when planning upgrades or tooling support.
Why version numbers and release dates matter
TypeScript follows semantic versioning for its public releases. A version number signals feature sets, language compatibility targets, and support windows. A release date anchors planning for builds, CI pipelines, and enterprise approval processes. Understanding both lets you balance new functionality against stability needs.
How we confirm a release date
- Official release notes published on the TypeScript blog
- Git tags and GitHub release artifacts for that version
- Package registry timestamps for the published npm package
TypeScript 1.2 notable features and changes
TypeScript 1.2 focused on language improvements and tooling stability. Key changes included enhanced type inference, support for more strict type checking options, and improvements to the language service used by editors.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Release date | September 21, 2016 | Release notes |
| Version | 1.2.0 | NPM and GitHub |
| TypeScript compiler target | ES3 and ES5 | Language spec |
| Key feature highlights | Const assertions, more strict type checking, improved inference | Changelog |
TypeScript 1.2 release highlights in brief
- Const assertions for more precise types
- Strict type checking options to catch common errors
- Improved language service responsiveness
- Bug fixes and compiler stability improvements
How to check your current TypeScript version
Use the TypeScript compiler to confirm the version installed on your machine or in your CI environment.
Using the CLI
tsc --versionThis prints the major.minor.patch version installed from npm or a manual install. Compare the output to 1.2.0 to verify you are on the intended release line.
Using package managers
In Node-based projects, check package.json and lockfiles for exact versions. For global installs, verify with tsc --version after the binary path.
Planning upgrades from TypeScript 1.2
Upgrading to newer TypeScript versions brings language features, performance improvements, and better editor integration. When planning upgrades from 1.2, review the changelog for breaking changes, test builds in a branch, and validate third-party library compatibility.
Upgrade checklist
- Read the release notes for the target version
- Run your test suite with the new compiler
- Check typings for external dependencies
- Update editor and tooling configurations as needed
Where to find official TypeScript release information
For the most accurate and up-to-date information, consult official sources maintained by the TypeScript team.
Key sources
- TypeScript blog and release notes
- GitHub releases page for TypeScript
- npm package page for TypeScript
- TypeScript documentation site for language spec
Summary and quick facts
TypeScript 1.2 was released on September 21, 2016 and remains a stable baseline for users on older toolchains. The release delivered meaningful quality-of-life improvements for developers and laid groundwork for subsequent language enhancements. Confirm your version with tsc --version and refer to official changelogs before upgrading.