1Password Safari extension causes cumulative performance degradation — 50%+ loss

1Password Version:
1Password for Mac 8.12.2 (81202037)

Extension version:
8.12.2.37

Host Machine:
M4 Pro Macbook Pro 16

I've been investigating 1Password extension performance on WebKit browsers and found a significant issue: the Safari extension leaks state across page navigations, causing performance to degrade sharply after the first page load cycle.

Baseline: Speedometer 3.1 (browserbench.org/Speedometer3.1/) in a single Safari window, fresh profile, no extensions.

- Run 1: 50.1 ± 3.3
- Run 2: 51.43 ± 0.36

With 1Password:

- Run 1: 41.6 ± 0.95 (~18% loss)
- Run 2: 21.0 ± 1.9 (~59% loss)
- Run 3: 22.9 ± 1.3 (~55% loss)

After restarting Safari (Cmd+Q):

- Run 1: 46.0 ± 2.4 (~10% loss)
- Run 2: 24.9 ± 2.3 (~51% loss)

Key findings:

1. First run after a fresh Safari launch shows a modest 10-18% hit — not great, but roughly expected for a password manager extension.
2. Second run onward, performance collapses to ~50-59% degradation and stays there.
3. Restarting Safari resets the issue, confirming it's accumulated state that isn't being cleaned up between page loads.
4. Variance also increases dramatically (±0.36 baseline vs ±1.9-2.4 with the extension), which explains the jittery/sluggish feel.

Why this matters beyond synthetic benchmarks:

This isn't just a synthetic benchmark issue. Speedometer works by rapidly creating and destroying DOM elements with input fields — which is exactly what happens during normal browsing as you navigate between pages. The extension appears to attach observers or event listeners that don't get torn down on navigation, causing cumulative overhead. This directly explains why Safari feels increasingly sluggish during a browsing session with 1Password enabled. This also applies to other webkit based browsers like Orion.

This issue has also been widely reported in the Orion browser community (orionfeedback.org/d/11861), where users see 60%+ degradation with the Chrome version of 1Password running through Orion's Web Extensions bridge. The assumption has been that Orion's compatibility layer is at fault. My testing shows the Safari native extension exhibits the same degradation pattern in Safari itself, which means the root cause is in 1Password's extension code, not in any specific browser's extension runtime.

Reproduction steps:

1. Open Safari with only the 1Password extension enabled
2. Navigate to browserbench.org/Speedometer3.1/
3. Run the benchmark — note the score (~40-45 on M4 Pro MBP)
4. Without restarting Safari, immediately run it again — note the score (~21-25)
5. Restart Safari and repeat — first run recovers, second run degrades again

I've been a happy user of 1Password for years and I think the security model of the Vaults is near perfection, but the extensions REALLY need work.

And to stave off any "Just use `Cmd+\`" comments: that is not a solution. I'm a heavy user of passcodes and I cannot use them in a browser without the extension.