GitHub's most recent Octoverse report, published in late 2025 and still the latest edition as of this writing, recorded a genuinely unusual shift: TypeScript became GitHub's most-used programming language, overtaking both Python and JavaScript. GitHub itself described it as the most significant language shift on the platform in more than a decade.

The numbers behind the shift

Contributor growth tells the story. TypeScript added roughly 1.05 million contributors over the year, up 66.6% — the fastest growth of the three. Python wasn't far behind in absolute terms, adding about 850,000 contributors for 48.8% growth. JavaScript grew the slowest of the group at 24.8%, adding around 427,000 contributors. Despite JavaScript's slower relative growth, GitHub noted that nearly 80% of new repositories on the platform still rely on just six languages: Python, JavaScript, TypeScript, Java, C++, and C#.

Separately, Stack Overflow's most recent Developer Survey (2025, the latest published edition) found Python used by about 55% of professional developers — the largest year-over-year gain of any major language — while TypeScript sat at roughly 48.8% usage among professionals. The two data sets measure different things (GitHub tracks contributions and repositories, Stack Overflow surveys usage directly), but together they paint a consistent picture: Python and TypeScript are both gaining ground, often at JavaScript's expense.

Why TypeScript specifically

TypeScript's rise tracks closely with the broader shift toward AI-assisted coding. Static typing gives both human reviewers and AI coding assistants more structure to work with — type errors get caught before code runs, and AI tools can generate more reliable suggestions when the codebase's types are explicit. As more teams lean on AI pair-programming tools for day-to-day development, that reliability advantage compounds, which plausibly explains why TypeScript adoption accelerated rather than plateaued.

What this means for your skill stack

Neither Python nor JavaScript is going anywhere — the six-language concentration GitHub reported shows the ecosystem is consolidating around a stable core, not fragmenting toward a single winner. But the specific trajectory is worth noting if you're choosing where to invest learning time:

• If you already know JavaScript, TypeScript is a comparatively low-cost upgrade — same ecosystem, added type safety — and current hiring demand increasingly expects it by default in frontend and full-stack roles rather than treating it as optional.
• Python's continued growth, especially its outsized year-over-year gain in the Stack Overflow data, reflects its entrenched position in data, AI/ML, and scripting work — it remains the safer general-purpose choice if you're starting from zero.
• For most working developers, the realistic answer isn't choosing one over the other — it's that fluency in both is becoming closer to a baseline expectation than a differentiator.

The next Octoverse edition, expected in late 2026, will show whether this is a durable shift or a one-year inflection — worth watching if you're planning a learning roadmap around it.