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Spark Speed vs FlyingPress: your pages stay on your own server
FlyingPress is known for strong defaults. It switches heavy optimizations on straight away and lets its own service do the work: the full HTML of every cached page is sent there. Spark Speed takes a different path. Everything happens on your own server, risky settings are tested first, and every automated change can be reverted.
In short
- FlyingPress sends the full HTML of every cached page to its optimizer service; Spark Speed does not
- Spark Speed checks every optimized page and falls back to the original when in doubt
- Object cache with four backends that never overwrites another plugin's
- Unlimited sites for €199.00 per year; FlyingPress Unlimited costs USD 279 per year
Your pages stay home
For unused CSS, critical images and fonts, FlyingPress posts the full rendered HTML of every page it caches to page-optimizer.flyingpress.com, together with your configuration and licence key. Spark Speed analyses on your own server. No extra processor in your privacy policy, and it keeps working when an external service is slow or unreachable.
Checking instead of hoping
Strong defaults are great until something breaks: a menu that does not open, a cart that does not update. Spark Speed checks every optimized page for broken HTML, compares the optimized version with the original during the first cache build, and has risky settings tested in a real browser first. If a script breaks, Spark Speed finds which one and excludes only that script.
Side by side
The differences we verified in the source code of both plugins.
| Feature | Spark Speed | FlyingPress |
|---|---|---|
| Where your pages are analysed | On your own server | Full HTML sent to the FlyingPress optimizer service |
| Checks every optimized page before it goes live | Yes, with fallback to the original | Not in the plugin code |
| Tests a risky setting in a real browser first | Yes (optimizer) | Not in the plugin code |
| Decision log with one-click revert | Yes | No |
| Refuses pages with session or login cookies and private cache headers | Yes | No |
| Object cache | Redis, Memcached, APCu or SQLite; never overwrites another plugin's | Redis only; overwrites existing drop-ins |
| Which plugin costs how many milliseconds | Yes (render profiler) | No |
| OPcache advice with concrete values | Yes | No |
| Database: autoload, Action Scheduler, Woo sessions | Yes, with a restore point | Revision limit only |
| Warmer checks that every page was really cached | Yes | Status code only |
| Self-hosts Google Fonts @import inside stylesheets | Yes | Partly |
| Icon fonts to inline SVG | Yes (Font Awesome Free 6) | No |
| Speeds up WP Grid Builder filters | Yes | No |
| Imports FlyingPress settings | Yes, as a preview first | Not applicable |
| WP-CLI in the plugin | 17 commands | 4 commands |
Where FlyingPress is stronger
FlyingPress switches heavy optimizations on straight away, generates missing srcset attributes, self-hosts YouTube thumbnails and third-party scripts, and shows visitor Core Web Vitals out of the box. Spark Speed only switches risky options on after a test and has visitor measurements off by default.
What we compared
The source code of FlyingPress 5.6.5 and Spark Speed 0.72.0, part by part: page cache, CSS and JavaScript, images, fonts, server and database, and what is sent to the makers. Every claim above was checked separately against the code. Where something is not in the plugin code but may exist in the maker's service, it says so. Reviewed on October 9, 2026.
Switching from FlyingPress? Spark Speed reads your FlyingPress exclusions and shows them as a preview first.
Everything on your own server, and it checks itself.
Frequently asked questions
No. Cache, unused CSS, LCP choice, image conversion and fonts run on your own server. Only the licence and update check contacts SparkCore.
Yes. Spark Speed recognises FlyingPress options and prepares your exclusions as a preview. Nothing is switched on without your approval.
Because the heaviest optimizations, such as delaying JavaScript, break menus or forms on some sites. Spark Speed tests them on your own pages first and only switches on what works.