Productivity
Letterboxx
Last updated 2026-07-21 · benchmark measured 2026-08-09 — deterministic & reproducible
Letterboxx is a Mac app for reading and organizing email newsletters.
Is Letterboxx production-ready?
Legit.Show scores Letterboxx 96 out of 100 — the simple average of its 7 measured frames. Legit.Show ran its deterministic 7-Frame production-readiness benchmark on Letterboxx (public-surface assessment), measured from the public surface with no LLM in the scoring path. Its strongest frame is Security; its weakest is Standards. Every frame it averages is published with its evidence on the Legit.Show listing.
The 7 Frames
- Performance — 96/100
- Accessibility — 93/100
- Security — 100/100
- Privacy — 100/100
- Reliability — 100/100
- Standards — 86/100
- Discoverability — 100/100
What we measured
- Security headers present: CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy.
- Served over HTTPS with a valid certificate.
- Real Lighthouse performance run — 988 ms to first byte.
- Returns a proper 404 for unknown routes.
- 3 of 3 sampled routes reachable.
- Has a reachable privacy policy.
- Sets cookies / loads scripts with no consent prompt.
- Discoverable: structured data, sitemap, OpenGraph image, canonical URL.
Who it's for
Newsletter subscribers · Mac users · Information readers · Research enthusiasts
Pricing
Monthly $4.99/month or Annual $39.99/year (save 33%); 14 days free trial
Visit Letterboxx → · Alternatives to Letterboxx → · How this was measured →