PHP 8.3 vs 8.4 vs 8.5: Full Performance Comparison (2026 Update)
PHP 8.5 was released in late 2025. Six months later, developers are still asking the same question: “Is it worth upgrading?” To answer this, we benchmarked PHP 8.3.30, 8.4.17, and 8.5.2 under three realistic workloads—light I/O, moderate I/O latency (50ms), and heavy I/O latency (200ms). The results reveal clear patterns, a surprising reversal, and a practical answer to the upgrade question.