The Data
WebPulse collects average pull request merge time from GitHub's API for every tracked framework. When we cross-referenced this metric with overall WebPulse scores, a pattern emerged that was stronger than we expected. Frameworks that merge pull requests in under 2 days consistently score above 73. Frameworks that take more than 4 days consistently score below 70. Flask — at 65.6 days average PR merge time — has the slowest merge velocity and one of the lowest overall scores (65.3).
The top five frameworks by PR merge speed are Astro (0.3 days), Next.js (0.5 days), Joomla (1.2 days), Remix (1.3 days), and SvelteKit (1.7 days). Four of the five score above 73 overall. The one exception — Joomla at 47.5 — is fast at merging PRs but carries the weight of 1,264 CVEs and declining market trajectory. PR merge speed predicts health. It does not override security debt.
Why Merge Speed Matters
PR merge speed is a proxy for three things that directly affect framework health. First, maintainer bandwidth — a project that merges PRs in hours has active, engaged maintainers. A project that takes months has maintainers who are overwhelmed, part-time, or disengaged. Second, contribution velocity — fast merges encourage more contributions. Slow merges discourage them, creating a negative feedback loop that shrinks the contributor pool. Third, security response time — a framework that can merge a security fix in 7 hours can ship a patch the same day a vulnerability is disclosed. A framework that takes 65 days cannot.
Flask's 65.6-day average is not a sign of careful review — it is a sign of a project with insufficient maintainer capacity. Flask is maintained primarily by a small team. The project has 71,640 GitHub stars (enormous) but only 2 releases in the last year and zero commits counted in the collection period. The gap between Flask's popularity (stars) and its maintenance velocity (PR merges) is the largest of any tracked framework.
The Tiers
The data clusters into three tiers. Tier 1 (under 2 days): Astro, Next.js, Remix, SvelteKit, Joomla, Laravel. These frameworks have professional-grade maintenance. Tier 2 (2–5 days): Rails (2.4), Nuxt (3.8), Gatsby (4.4). These have active maintenance but slower review cycles. Tier 3 (over 5 days): Django (25.0), Flask (65.6). These have maintenance bottlenecks that affect every aspect of the framework's evolution.
The tier boundaries are not arbitrary — they correspond to observable score clusters. Tier 1 frameworks average 76.1 overall (excluding Joomla). Tier 2 frameworks average 72.5. Tier 3 frameworks average 66.9. A 9-point gap between the fastest and slowest tiers, driven by a single operational metric.
What This Means for Framework Selection
PR merge speed is not typically considered in framework evaluations. Feature lists, performance benchmarks, and community size dominate the decision. But WebPulse's data suggests that merge speed is one of the strongest single predictors of overall framework health — stronger than GitHub stars, stronger than community size, and more predictive than feature comparisons. When evaluating a framework, check how long it takes to merge a pull request. If the answer is measured in weeks, the framework's future is uncertain regardless of its current popularity.
