Stealth Analytics Script Size vs. GA4, Simple Analytics, and Plausible

Stealth Analytics ships a 0.7 KB frontend payload, the smallest of the four tools compared on its own site. That number matters if you are trying to protect a Lighthouse performance score or a Core Web Vitals budget: a smaller script downloads, parses, and executes faster, and Stealth Analytics states its script is engineered to load in milliseconds without blocking rendering. The comparison below uses the figures published on Stealth Analytics' own site, so treat the other vendors' numbers as Stealth's characterization rather than independently verified measurements.

Script size comparison

The gap between GA4 and the rest is roughly an order of magnitude. GA4 is also the only tool here that is typically loaded through Google Tag Manager or a gtag.js snippet, which can pull in additional requests beyond the base script. Stealth Analytics, Simple Analytics, and Plausible all position themselves as lightweight alternatives, and their listed sizes cluster within a few kilobytes of each other.

What the 0.7 KB figure does and does not cover

Stealth Analytics describes its frontend script as "microscopic" and says it is "virtually invisible to the browser." The 0.7 KB refers to that frontend script. The product also supports a second ingestion path: you can skip the browser script entirely and send a standard JSON payload via POST to its edge endpoint from any language or framework. In that mode there is no frontend script at all, so the 0.7 KB does not apply to your page weight.

The site's headline is "If it can make a POST request, we can track it," and it lists REST API ingestion, backend system events, and mobile-optimized dashboards as first-class features rather than add-ons.

Why script size is only part of the performance question

A small script is necessary but not sufficient for a clean performance score. Three things determine the real cost:

1. Transfer size vs. parse/execute cost. A 0.7 KB file is trivial to download, but the JavaScript still has to be parsed and run. Stealth Analytics claims millisecond load times and no render blocking; those are the claims to verify with your own Lighthouse or WebPageTest run.
2. Request count. One small script is better than one small script plus a tag manager plus a consent wrapper. If you use Stealth's API path instead of the script, you can remove the request from the critical path entirely.
3. What you actually measure. If you only need pageviews, a 0.7 KB script is plenty. If you need custom events, Stealth Analytics supports them, but the free tier caps you at 2 custom events per project, so the practical ceiling depends on your plan.

Choosing based on this comparison

• If your priority is the smallest possible browser payload, Stealth Analytics at 0.7 KB is the lowest number in this set, and its API-first design lets you avoid a frontend script altogether.
• If you want a mature, widely documented ecosystem and can absorb the weight, GA4 is the heaviest option here by a wide margin.
• If you want a lightweight script with a longer track record in the privacy-first analytics space, Simple Analytics (~3.0 KB) and Plausible (~1.2 KB) sit between the two extremes.

One caveat on pricing: Stealth Analytics lists a free tier (5,000 events, 30-day retention) and paid tiers at $14/mo and $39/mo, and its pricing section mentions "upgrade" but no payment platform details are given on the page. Confirm current terms on the site before committing, and note that the free tier's 2-custom-events limit may matter more to your setup than the 0.7 KB script size.