This is probably not news to anyone who has been working in the eCommerce industry for some time: Speed equals revenue.Just a one-second increase in the loading speed of your web page may significantly reduce your conversions.
Theme designers always advertise their themes as “the fastest Shopify theme ever,” but how often is that true?
To find out, I took five highly popular Shopify themes—Turbo, Shella, Electro, Impact, and Booster—and ran them through Google PageSpeed Insights. We aren’t just looking at desktop scores; we are diving deep into the grueling mobile performance metrics, where most themes stumble.
Here is the real, raw data, ranked from fastest to slowest based on overall mobile performance.
1. Turbo (by Out of the Sandbox)
- Best For: High-volume stores needing uncompromising mobile speed.
- Price: $380
- Demo: Automobile Engine Oil Preset
Turbo has built a legendary reputation for speed, and the data proves it isn’t just hype. Scoring an incredibly rare 92 on Mobile Performance, this theme is an absolute powerhouse. Most Shopify themes struggle to break a 70 on mobile, making Turbo a top-tier investment for serious merchants.
Google PageSpeed Insights Data:
| Metric | Desktop | Mobile |
|---|---|---|
| Performance Score | 92 | 92 |
| Accessibility | 90 | 90 |
| Best Practices | 96 | 96 |
| SEO | 85 | 85 |
| Agentic Browsing | 2/3 | 2/3 |
| First Contentful Paint (FCP) | 0.7 s | 2.6 s |
| Largest Contentful Paint (LCP) | 1.4 s | 8.2 s |
| Total Blocking Time (TBT) | 70 ms | 20 ms |
| Cumulative Layout Shift (CLS) | 0.088 | 0.001 |
| Speed Index | 1.5 s | 3.7 s |
2. Shella (by MPIThemes)
- Best For: Fashion boutiques looking for premium features on a budget.
- Price: ~$69 USD
- Demo: Shella Demo Store
Shella is a heavyweight champion on desktop, hitting a near-perfect 99 Performance score. While its mobile score dips to 78, this is still incredibly strong for a feature-heavy fashion theme. With an insanely fast desktop First Contentful Paint (FCP) of just 0.4 seconds, Shella offers premium speeds at a fraction of the cost of other themes.
Google PageSpeed Insights Data:
| Metric | Desktop | Mobile |
|---|---|---|
| Performance Score | 99 | 78 |
| Accessibility | 82 | 84 |
| Best Practices | 96 | 96 |
| SEO | 100 | 100 |
| Agentic Browsing | 2/3 | 2/3 |
| First Contentful Paint (FCP) | 0.4 s | 1.7 s |
| Largest Contentful Paint (LCP) | 0.9 s | 5.4 s |
| Total Blocking Time (TBT) | 20 ms | 90 ms |
| Cumulative Layout Shift (CLS) | 0 | 0 |
| Speed Index | 1.0 s | 3.0 s |
3. Electro (by SalesHunterThemes)
- Best For: Consumer electronics stores with large, spec-heavy catalogs.
- Price: $200 USD
- Demo: Electro Demo Store
Designed specifically for complex tech catalogs, Electro holds its own nicely. It boasts an excellent 96 Desktop Performance and a highly respectable 70 on Mobile. Impressively, its mobile FCP is a blistering 0.5 seconds, meaning the site visually loads for mobile users almost instantly, keeping bounce rates low.
Google PageSpeed Insights Data:
| Metric | Desktop | Mobile |
|---|---|---|
| Performance Score | 96 | 70 |
| Accessibility | 90 | 97 |
| Best Practices | 92 | 92 |
| SEO | 92 | 92 |
| Agentic Browsing | 2/3 | 2/3 |
| First Contentful Paint (FCP) | 2.6 s | 0.5 s |
| Largest Contentful Paint (LCP) | 7.2 s | 1.3 s |
| Total Blocking Time (TBT) | 10 ms | 10 ms |
| Cumulative Layout Shift (CLS) | 0 | 0 |
| Speed Index | 4.0 s | 1.4 s |
4. Impact (by Maestrooo)
- Best For: Modern DTC brands relying on bold typography and heavy imagery.
- Price: $400 USD
- Demo: Impact Sound Preset
Impact is visually stunning and packed with native features to replace third-party apps, which justifies its premium price tag. However, because it relies on large, editorial-style imagery, it takes a slight hit on PageSpeed Insights. It secures an 85 on Desktop and a 67 on Mobile. While the Largest Contentful Paint (LCP) on mobile is a bit high at 11.0 seconds, its Total Blocking Time is virtually zero, meaning the site remains highly responsive as it loads.
Google PageSpeed Insights Data:
| Metric | Desktop | Mobile |
|---|---|---|
| Performance Score | 85 | 67 |
| Accessibility | 81 | 81 |
| Best Practices | 96 | 96 |
| SEO | 54 | 54 |
| Agentic Browsing | 2/3 | 2/3 |
| First Contentful Paint (FCP) | 0.6 s | 2.6 s |
| Largest Contentful Paint (LCP) | 2.0 s | 11.0 s |
| Total Blocking Time (TBT) | 0 ms | 10 ms |
| Cumulative Layout Shift (CLS) | 0.001 | 0 |
| Speed Index | 2.5 s | 5.5 s |
5. Booster Theme
- Best For: Merchants looking for an all-in-one theme to replace multiple paid apps.
- Price: $169/yr or $249 Lifetime
- Demo: Booster Theme via ThemeAura
Booster Theme markets itself aggressively as a conversion-boosting, all-in-one solution. On desktop, it absolutely flies with a 97 Performance score and a near-instant 0.5s FCP. However, it struggles a bit on mobile, pulling a 64 Performance score. Given how feature-dense this theme is, a 64 on mobile is fairly standard, but you will want to optimize your images carefully if you use it.
Google PageSpeed Insights Data:
| Metric | Desktop | Mobile |
|---|---|---|
| Performance Score | 97 | 64 |
| Accessibility | 86 | 92 |
| Best Practices | 96 | 96 |
| SEO | 92 | 100 |
| Agentic Browsing | 2/3 | 2/3 |
| First Contentful Paint (FCP) | 0.5 s | 3.8 s |
| Largest Contentful Paint (LCP) | 1.2 s | 9.0 s |
| Total Blocking Time (TBT) | 0 ms | 0 ms |
| Cumulative Layout Shift (CLS) | 0.001 | 0.001 |
| Speed Index | 0.7 s | 5.2 s |
The Final Verdict: Which Theme Should You Choose?
Numbers don’t lie. If you want uncompromising speed across all devices, Turbo is in a league of its own, mastering mobile performance in a way few themes can. If you are on a budget but still want elite desktop speeds, Shella is a fantastic steal.
For visual-heavy and feature-dense brands, Impact and Booster are still highly viable options—just remember that you are trading a few points of mobile speed for gorgeous native layouts and built-in sales tools.
Which theme are you running right now? Have you tested its speed recently? Let us know in the comments below!