Which PHP Version Is Fastest for WordPress in 2025? Benchmarks and Recommendations

Shockingly, a controlled test found sites running PHP 8.3 handled 169 requests per second — over 13% faster than 7.4. That gap translates into real user-visible speed and lower server load for your site.

PHP 8.3 landed in November 2023 with new functions, readonly class upgrades, Randomizer additions, and stack overflow detection that help make modern builds snappier.

We’ll compare current php versions head-to-head using fresh lab benchmarks so you can pick a safe update path without risking downtime.

This article blends raw numbers — like 149 req/s on older stacks versus 169 req/s on 8.3 — with practical guidance. You’ll learn why OPcache, PHP-FPM, and sane server settings matter as much as the core runtime.

• PHP 8.3 shows clear speed gains and useful new features that benefit modern sites.
• Benchmarks reveal meaningful request/sec and response-time improvements for typical setups.
• Updating safely means testing plugins, enabling OPcache, and checking PHP-FPM settings.
• Older stacks like 7.4 still exist, but they lag in speed and security support.
• Follow a staged update plan to boost speed while keeping downtime risk low.

You want a faster site in 2025, but not at the cost of breaking plugins or custom themes. Many websites still run older runtimes because compatibility concerns with plugins, themes, or bespoke code make admins cautious.

Upgrades can be safe. Hosting providers often let you switch with one click, and benchmarks show big gains moving from 7.x to 8.0+ — with 8.3 delivering top throughput in modern tests.

“Test on staging, have a rollback plan, and validate logged-in flows — then measure before and after.”

• Pick a release that lifts speed while staying inside your comfort zone for compatibility.
• Plan staged updates, sanity checks for users, and a short rollback window.
• Keep security and support lifecycles in mind: out-of-support runtimes put your website at risk.

Each runtime release shifts CPU use, memory needs, and the number of users your server can serve at once.

Execution speed improved dramatically with the move from 7.x to 8.0 thanks to JIT and internal optimizations. Later releases trimmed memory use and added engine tweaks that boost throughput on modern stacks.

Newer releases lower CPU load by running common operations faster and using memory more efficiently. That means faster TTFB and more requests per second for your site.

Enable OPcache and PHP-FPM to let those engine gains translate into real user-visible speed and higher concurrency.

Many sites stay on older runtimes because plugins, themes, or custom code may break after an update. Hosts also sometimes delay pushing upgrades.

“If support ends, you stop getting fixes—so the security risk grows even if the site appears stable.”

• Security: each release patches unsafe behaviors and improves cryptography.
• Support: end-of-life means no more security fixes for older stacks.
• Upgrade trade-off: compatibility vs. risk and long-term speed gains.

Don’t treat a single chart as gospel — test conditions drive the results. Lab setups, page mixes, and hardware all shape which build looks fastest.

Pressidium’s WordPress-only test used WordPress 6.5.5, Twenty Twenty-Four, no plugins, OPcache on and server caching off. The test client ran in the same cluster to cut network noise. They used 50 concurrent users with a ramp-up, two minutes at peak, and tracked mean processing and response time every second. That mix—homepage plus login/register flows—stressed dynamic code paths and highlighted a clear gain at PHP 8.0 while later releases showed mixed results.

Kinsta’s multi-CMS run targeted default homepages across platforms on a beefy GCP C2 host (30 cores, 120GB). With nginx‑fpm, MariaDB, and lower concurrency (15), the results emphasized raw req/s where newer releases climbed steadily to 8.3.

• If a chart crowns one build, check concurrency, pages tested, and CPU/RAM—those variables can flip the leaderboard.
• Cached homepages, carts, and login flows expose different bottlenecks; pick tests that mirror your site.
• Both providers minimized network jitter by colocating clients, so the measured response and processing time reflect runtime behavior.

“Benchmark the same pages and load your users generate — that’s the only way to pick a winner for your website.”

Side-by-side benchmarks reveal where your site wins — and where upgrades give little or no lift. The raw numbers show a clear first move and a separate trend for modern stacks.

Pressidium recorded mean processing times of 68.6 ms on php 7.4 and 51.1 ms on php 8.0. That drop cut mean response time from 91.7 ms to 67.1 ms under a 50-user load.

Later releases were less consistent: 8.1 showed 71.3 ms processing and 94.7 ms response, while 8.2 landed near 67.2 ms processing and 90.4 ms response. Total requests stayed similar across runs.

Kinsta’s WordPress throughput shows a steady rise in req/s: for WP 6.4.2 it goes 149 (7.4) → 153 (8.1) → 158 (8.2) → 169 (8.3). A similar trend appears for WP 6.2.2, with 165 req/s on 8.3.

• Biggest single leap: moving off php 7.4 to php 8.0 delivers the most reliable latency gains in heavy, uncached tests.
• Mixed mid-releases: 8.1 and 8.2 can vary depending on theme, plugins, and server tuning.
• Throughput champion: in tuned, throughput-first stacks, 8.3 posts the highest req/s.

“If your site matches Pressidium’s heavier, no-cache workload, 8.0 is the safest fast move; for modern tuned stacks, 8.3 trends fastest.”

Your action: test on staging with your plugins and pages, measure TTFB and latency, then pick the release that wins for your site rather than a generic chart.

Real-world tests in 2025 show newer runtimes usually serve more requests per second, but the win depends on load and stack tuning.

On a GCP C2 test with WordPress 6.4.2 and 15 concurrent users, throughput climbed as builds advanced: 7.4 → 149 req/s, 8.1 → 153, 8.2 → 158, and 8.3 → 169.

Pressidium’s heavier, no-cache run (50 users, OPcache on) showed the biggest latency drop when moving off php 7.4 to 8.0. Later mid-releases were mixed depending on the workload and plugins.

“Test results are directional — your stack and traffic mix decide the real gain.”

• Zooming out: newer releases trend faster for most sites, especially on tuned servers.
• Biggest safe jump: 7.4 → 8.0 in heavy, dynamic tests.
• Throughput leader: 8.3 often posts the highest req/s on modern setups.

Practical takeaway: move off php 7.4, validate on staging, and pick the newest supported release your site and plugins handle. Then measure request rates, CPU, and response time to lock in gains.

Pick the path that matches your risk appetite and maintenance cadence. Small teams and older stacks often need a low-drama move. Larger, well-maintained sites can chase peak throughput.

PHP 8.0 is the sensible midpoint if compatibility matters most. Tests show the biggest single latency drop when moving off 7.4 to 8.0 in WordPress-only runs.

If plugins or custom code have tripped on newer releases before, 8.0 gives a large speed win with fewer breaking changes. It’s also a good step if you want a short staging cycle, quick rollback, and minimal surprises.

PHP 8.3 pulls ahead on tuned, throughput-first stacks. Multi‑CMS benchmarks report higher req/s as builds advance to 8.3, and it includes added security and engine tweaks.

If your theme and plugins are updated, hosting is modern, and you can test deeply on staging, 8.3 gives the best chance at raw speed and long-term support benefits.

“Test on staging, measure TTFB and error rates, then pick the release that wins for your site.”

• Quick wins: go 8.0 for a low-risk uplift.
• Top throughput: go 8.3 when you can validate changes safely.
• Always: run a short staging cycle to confirm carts, logins, and key flows before switching production.

Treat upgrades as a sequence of small, verifiable steps. Start in staging, mirror real data, and run the exact flows your users hit most. This lowers risk and makes troubleshooting fast.

Progressive upgrades work best: move from 7.4 → 8.0 → 8.1 → 8.2 → 8.3, testing at each stop so you isolate failures quickly.

• Audit plugins and themes: check last-update dates and changelogs for PHP 8 support and any reported fatal errors.
• Run Query Monitor or Tideways on staging to catch deprecations, slow queries, and uncaught exceptions.
• Keep a rollback snapshot and perform changes during low-traffic windows to protect revenue.

“Spin up a mirror of production, run smoke tests on forms and carts, then iterate — that’s the safe path.”

A few configuration changes—FPM pools, OPcache sizing, and Apache rules—sharpen how your site handles load. These tweaks help turn engine features into steady, measurable gains for your web platform.

Start with pm=dynamic and tune pm.max_children, pm.start_servers, pm.min_spare_servers, pm.max_spare_servers, and pm.max_requests to match RAM and traffic. Example starter values: pm.max_children=50, pm.start_servers=5, pm.min_spare_servers=5, pm.max_spare_servers=35.

Load test to find the sweet spot so the server handles more concurrent requests without swapping or crashes.

Enable OPcache in php.ini with opcache.enable=1 and set opcache.memory_consumption=128 (increase for heavier sites). This caches compiled code so CPU use and response time drop on repeat hits.

Enable HTTP/2 or HTTP/3 via your providers or platform to lower latency. Use gzip, mod_expires, and long-lived asset caching. Move complex .htaccess rules into the main config and proxy to FPM to cut per-request file checks.

“Right-sized worker pools and bytecode caching deliver the best balance of throughput and stability.”

When you add object caching and an edge CDN, your database stops becoming the bottleneck. Many sites run the same queries over and over. That wastes CPU and slows pages for both admins and visitors.

Use in-memory stores like Redis or Memcached to keep query results and transients ready in RAM. This is especially helpful for logged-in users and busy WooCommerce carts where caching full pages isn’t possible.

Redis and Memcached reduce round trips to your database by serving common objects instantly. Popular plugins like Redis Object Cache and W3 Total Cache make integration simple.

Result: lower DB load, fewer slow queries, and more CPU left for rendering pages using php.

Combine an in-memory object cache with a reputable CDN so images, scripts, and styles come from the nearest edge location. That lowers latency across regions.

Enable HTTP/2 or HTTP/3 at your hosting or edge to unlock multiplexing, header compression, and QUIC benefits on unstable networks.

• Add Redis or Memcached object caching to cut repeated database queries for logged-in sessions and carts.
• Store transients and query results in RAM to free CPU cycles and speed rendering.
• Pair server-side caching with a CDN so static content reaches users from the closest edge.
• Using php efficiently with these layers means fewer slow queries and smoother peak-time behavior.
• Keep configuration observable to spot cache misses and tune TTLs without breaking freshness.

For a practical starter, follow a short staging test: enable object caching, run key flows, then add the CDN and flip HTTP/2/3 at your hosting edge. If you want setup tips, see this object caching guide.

Start by defining the exact question your test should answer — latency under load, raw throughput, or error resilience. That clarity keeps your test focused and your results useful.

Run a 50 virtual-user (VU) load test to see stability and processing time under pressure. Pressidium used 50 concurrent threads with a ramp-up and 1-second aggregation to measure processing latency on pages like the homepage and login flows.

Run low-concurrency tests to measure raw req/s. Kinsta used ab with concurrency 15 and 1,000 requests to highlight throughput differences across builds.

• ab — quick, repeatable req/s checks you can script.
• New Relic — production-grade tracing for errors and slow code paths.
• Query Monitor and Tideways — pinpoint slow queries, hooks, and template code on staging.

Track TTFB or processing time, requests per second, and error rate together. High throughput with rising errors or slow response time is a false win.

Pick a path that matches how your site is used and how much risk you can accept. Content-heavy sites can usually move faster, while commerce and custom platforms need staged work with good observability.

If your site is mostly static or content-driven, jump to the newest supported release you can validate. Fewer plugins and simple themes make compatibility checks quick. You get speed and security gains with minimal staging time.

For carts, subscriptions, and logged-in flows, treat upgrades like a mini release. Test checkouts, emails, and session handling on staging. Benchmarks show WooCommerce gains at the top end (8.3 -> largest req/s), but real-world checkout logic can hide regressions.

Large codebases should phase 7.4→8.0→8.1→8.2→8.3 using CI, unit tests, and error tracing. That catches incompatibilities early and limits blast radius.

“If you’re still on php 7.4, plan a move: it’s out of active support and leaves your website exposed.”

• If uptime is critical: consider 8.0 as the conservative first stop; it often gives the biggest safe latency improvement from older php 7.4 stacks.
• For modern platforms: aim for 8.3 to capture top throughput, after thorough validation of plugins, themes, and custom code.

Start with a practical checklist that turns upgrades from a gamble into a repeatable process. The goal is simple: move safely, measure quickly, and lock in gains so your site stays fast and secure.

First: update the CMS core, themes, and plugins on a staging clone and take a full snapshot before you change anything.

Switch php on staging, then run a short test suite: homepage, key landing pages, forms, login, and checkout if you have one. Fix errors and retest.

Promote to production during a low-traffic window. Watch logs and APM dashboards like New Relic, plus Query Monitor or Tideways, and be ready to roll back if needed.

Iterate toward newer releases as you gain confidence. Recheck OPcache, tune PHP-FPM pools, and monitor Redis/Memcached cache health so speed sticks over time.

• Back up and snapshot before each major update.
• Validate key flows on staging before promoting.
• Flip during low-traffic windows and monitor closely.
• Re-benchmark quarterly to catch regressions after plugin or theme changes.

“Progressive updates, careful staging, and routine maintenance turn short wins into lasting gains.”

Here’s the short, practical takeaway to help you plan safe updates and measurable gains.

Move off php 7.4 first — you get better speed, improved security, and restored support. In multi‑CMS benchmarks, 8.3 often leads on raw req/s, while WordPress‑only tests show the biggest latency drop when moving from 7.4 to 8.0.

Choose 8.0 for the safest fast upgrade or 8.3 for top speed if your plugins and themes pass staging checks. Remember: engine releases are only part of the story.

Enable OPcache, tune PHP‑FPM pools, and benchmark your pages. Watch TTFB, req/s, and error rates so speed improvements don’t harm stability.

Keep iterating with scheduled updates so your websites stay quick, secure, and aligned with new release improvements.