Developer Tools

FadSync

Last updated 2026-07-23 · benchmark checked 2026-09-13 · unchanged since 2026-08-08 — deterministic & reproducible

FadSync is an API for detecting disposable and burner email addresses.

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To cite this score: legit.show/s/mailcheck-fadsync-com/2026-09-13. That address never changes; this page moves with every re-measure.

Legit.Show scored FadSync 78/100 on 2026-09-13, measured across all 7 frames from its public surface. legit.show/s/mailcheck-fadsync-com/2026-09-13

Is FadSync production-ready?

Legit.Show scores FadSync 78 out of 100 — the simple average of its 7 measured frames. Legit.Show ran its deterministic 7-Frame production-readiness benchmark on FadSync (public-surface assessment), measured from the public surface with no LLM in the scoring path. Its strongest frame is Privacy; its weakest is Security. Every frame it averages is published with its evidence on the Legit.Show listing.

The 7 Frames

• Performance — 54/100
• Accessibility — 96/100
• Security — 45/100
  How this compares across the catalogue: The Web Security Baseline
• Privacy — 100/100
  How this compares across the catalogue: The Privacy Gap
• Reliability — 75/100
• Standards — 92/100
• Discoverability — 85/100

What we measured

• Security headers present: X-Content-Type-Options, Referrer-Policy.
• No Content-Security-Policy and no HSTS.
• Served over HTTPS with a valid certificate.
• Real Lighthouse performance run — 398 ms to first byte.
• 3 of 3 sampled routes reachable.
• Has a reachable privacy policy.
• Sets cookies / loads scripts with no consent prompt.
• Discoverable: sitemap, OpenGraph image, canonical URL.

Who it's for

Developers · SaaS platforms · User authentication systems · Email delivery services · Enterprise security teams

Pricing

Free tier (250 requests/month); Pro $15/month (10K requests/month); Ultra $49/month (50K requests/month); Mega $149/month (250K requests/month); custom enterprise plans available

Sources and updates

Description

Taken from mailcheck.fadsync.com's own website on 2026-07-23.

Operator

FadSync Development Studio, as named in mailcheck.fadsync.com's terms, privacy page or footer.

Benchmark

Measured by Legit.Show from the live site, the way any visitor sees it — with no access to its code or accounts. Same method for every product, and no AI decides the score. Last checked 2026-09-13.

Put together from public information, without FadSync's involvement. If anything here is wrong, tell us and a person will check it.

Visit FadSync → · Alternatives to FadSync → · How this was measured →