TIOBE published its September 2026 programming language index this week, and the headline number is real: Rust has broken into the top 10 for the first time in the index's history. Python is still comfortably in first place, but its rating keeps eroding. Here's what actually changed, and — more usefully — what it should and shouldn't change about what you decide to learn next.
The top 10, as of this month
TIOBE's rating isn't a measure of how much code is actually running in production — it's built from search-engine query volume for "<language> programming," which makes it a decent proxy for developer attention and learning interest, not for hiring demand or deployed codebases. With that caveat up front, here's where things landed:
- 1. Python — 17.76% (down 8.22 points year-over-year)
- 2. C — 10.28% (up 1.63 points)
- 3. C++ — 8.67% (down 0.13 points)
- 4. Java — 7.54% (down 0.81 points)
- 5. C# — 4.22% (down 2.16 points)
- 6. JavaScript — 2.76% (down 0.46 points)
- 7. Visual Basic — 2.55% (down 0.28 points)
- 8. SQL — 2.16% (up 0.29 points)
- 9. R — 1.69% (up 0.27 points)
- 10. Rust — 1.34% (up 0.33 points) — a first-ever top-10 finish
Rust's climb pushed Go out of the top 10 entirely — Go dropped 1.22 points to land at 12th place this month, the sharpest single-month fall of any language currently in the top 15. It's worth sitting with how unusual that top 10 list actually is: five of the ten languages (C, C++, Java, JavaScript, and now Rust joins a group that also includes SQL) have been fixtures of professional software development for a decade or more, while C# and Visual Basic represent Microsoft's enterprise stack and R represents statistics and data science. Rust is the only genuinely "new" language — first stable release in 2015 — to break into that group in years.
Why Rust's move actually means something
A single month's index shift is noise on its own, but Rust's trajectory over the last few years hasn't been a spike — it's been a steady climb, driven by real, visible adoption: it's the default choice for new CLI tooling, it's showing up inside performance-critical layers of projects historically written in C or C++ (parts of the Linux kernel, browser engine components, and a growing share of new backend infrastructure), and its compiler's borrow-checker pitch — memory safety without a garbage collector — keeps converting people who tried it once for a side project and didn't go back. Cracking the top 10 is TIOBE catching up to something that was already true in practice: Rust stopped being a "should I bother learning this" language a while ago.
What it doesn't mean is that Rust is now more in-demand than Java or C++ for jobs — TIOBE explicitly isn't a hiring-demand metric, and the job market for Rust, while growing fast in percentage terms, is still a fraction of the size of the ecosystems around it. Treat this as a strong "worth learning if you haven't" signal, not a "switch your whole stack" signal.
Python's slide, and why it's not the story you might think
Python losing over 8 rating points in a year sounds dramatic, and headlines will frame it that way. Two things temper that: first, TIOBE's rating is a percentage of search share across dozens of tracked languages, so as more niche and specialized languages get their own search volume (R, Rust, and others gaining ground this month included), everyone's slice of the pie shrinks a bit — it doesn't mean fewer people are searching for Python in absolute terms. Second, Python is still miles ahead of second place, and it remains the default teaching language, the default glue language for data work, and — this is the part that matters most for readers of this blog — still the dominant language sitting underneath the AI tooling ecosystem, from model training scripts to most agent frameworks. If you're on our AI track, nothing about this month's index changes what you should be doing.
What this means if you build mobile apps
Two mobile-adjacent languages moved up this month: Swift climbed to 18th (0.83%, up 0.10 points) and Objective-C climbed to 19th (0.81%, up 0.32 points) — both re-entering the top 20 after Perl and Ruby dropped out of it. Kotlin still sits outside the top 20 in TIOBE's search-based methodology despite being the default language for new Android development, which is the clearest reminder that this index tracks search-engine attention, not what's actually shipping on the Play Store or App Store. If you're deciding what to learn for mobile work, use our Android, iOS, Flutter, or React Native tracks to decide based on the platform and job market you're targeting — not this month's search-volume snapshot.
The quieter story: old languages are having a moment
The most unusual line in this month's report isn't in the top 10 at all. Ada and Objective-C both re-entered TIOBE's top 20 this month, both showing what the index's own commentary called "renewed strength" despite being multi-decade-old languages. Meanwhile Julia — a language built for numerical and scientific computing — sits just outside the top 20 at 21st place (0.74%), continuing to eat into MATLAB's territory alongside Python and R, though TIOBE's own analysis is careful to note Julia "remains concentrated in relatively niche domains and has not yet managed to break through as a general-purpose programming language." Worth watching, not worth switching your stack over yet.
So what should you actually learn?
Read this index the way it's meant to be read: as a slow-moving weather report on developer attention, not a to-do list. Practically, that means:
- If you're building for mobile, the platform you're targeting still decides your language — Kotlin and Swift for native, Dart or JavaScript/TypeScript for cross-platform — regardless of where they sit in a search-volume index.
- If you're doing anything data- or AI-adjacent, Python's continued dominance here (even in decline) confirms it's still the safest first language to learn for that work.
- If you want a language that's clearly gaining real momentum and not just search buzz, Rust's multi-year climb into the top 10 is the most credible "worth the investment" signal in this month's report.
- If you're already comfortable in C or C++ and have been on the fence about picking up something new for systems-level or performance-critical work, Rust's steady rise (rather than a one-month spike) is a reasonable signal that the investment will keep paying off rather than fading as a fad.
None of this is a reason to panic-switch what you're learning based on a single monthly report. TIOBE is best used the way a good developer uses any metric: as one input among several, cross-checked against what job postings in your target market actually ask for, and against what you'd actually enjoy building things with. The index is a useful early-warning signal for which languages are gaining real traction versus which are fading — it's a poor tool for picking your very first language, and a genuinely useful one for deciding what your second or third language should be.