OnlineOrNot vs Sematext: Simple Playwright Quotas or Flat Per-Monitor?

OnlineOrNot and Sematext both appeal to teams that want browser synthetics without Checkly-scale MaC or Catchpoint-scale DEM. OnlineOrNot sells a compact plan with included Playwright/Chrome runs and overage. Sematext sells a flat per-browser-monitor price with almost no run math.

Neither replaces a suite platform. Both can be "good enough" for a handful of journeys if you accept thinner developer surfaces. Category context: best synthetic monitoring tools.

TL;DR

How the bills diverge

OnlineOrNot includes 3,000 browser runs on Pro ($4/1k after). A single check every 30 seconds is 86,400 runs/month from one location. That overruns the included quota fast unless you slow the interval or reduce regions. At five-minute cadence, the same check is 8,640 runs/month and fits more comfortably.

Sematext's ~$7 flat per browser monitor ignores run count inside their floors. Ten browser monitors ≈ $70/month whether you are near the 5-minute floor or somehow denser within product limits. You pay for predictability with slower default detection (5-minute browser floor).

Product shape

OnlineOrNot: uptime + API + browser + heartbeats + status page, indie UX, unlimited Pro users. Strong "small SaaS monitoring kit."

Sematext: synthetics as a slice of a wider observability suite. Docker private locations are a real advantage for internal apps. Forensics and MaC for synthetics stay thin versus Checkly.

Shared Playwright-shaped check:

import { test, expect } from "@playwright/test";

test("health UI", async ({ page }) => {
  await page.goto("https://status-admin.example.com/login");
  await page.getByLabel("Email").fill(process.env.SYNTHETIC_EMAIL!);
  await page.getByRole("button", { name: "Sign in" }).click();
  await expect(page.getByText("All systems")).toBeVisible();
});

Who should choose which

Choose OnlineOrNot if you want 30-second intervals on a simple Pro plan and can keep browser-run count inside quota.

Choose Sematext if a fixed per-monitor monthly number matters more than sub-5-minute browser detection, or you need Docker private locations.

Both still leave API/dependency monitoring as a separate job. DevHelm covers that layer with flat pricing, assertions, and config-as-code. First monitor in about 60 seconds, no credit card.