Legit.Show measured 501see's Security frame at 25/100. No Content-Security-Policy and no HSTS. Served over HTTPS with a valid certificate.

How does Legit.Show measure 501see?

Legit.Show scores seven frames — Performance, Accessibility, Security, Privacy, Reliability, Standards and Discoverability — deterministically from the public surface (URL, HTTP headers, real Lighthouse), with no LLM in the scoring path. See legit.show/methodology.

Developer Tools

501see

Last updated 2026-08-26 · benchmark measured 2026-09-27 — deterministic & reproducible

Self-serve API for nonprofit and IRS 990 data, no sales process required.

77/100

7/7 frames

Top 54% of 14,148 measured

Legit Benchmark — the simple average of 7 measured frames. Frames we could not measure are left out of the average, never counted as zero. Every frame is shown below with its evidence.

Checked 2026-09-27 · scores move as sites change

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To cite this score: legit.show/s/developers-501see-app/2026-09-27. That address never changes; this page moves with every re-measure.

Legit.Show scored 501see 77/100 on 2026-09-27, measured across all 7 frames from its public surface. legit.show/s/developers-501see-app/2026-09-27

Is 501see production-ready?

Legit.Show scores 501see 77 out of 100 — the simple average of its 7 measured frames. Legit.Show ran its deterministic 7-Frame production-readiness benchmark on 501see (public-surface assessment), measured from the public surface with no LLM in the scoring path. Its strongest frame is Reliability; its weakest is Security. Every frame it averages is published with its evidence on the Legit.Show listing.

The 7 Frames

Performance — 67/100
Accessibility — 93/100
Security — 25/100
How this compares across the catalogue: The Web Security Baseline
Privacy — 75/100
How this compares across the catalogue: The Privacy Gap
Reliability — 100/100
Standards — 92/100
Discoverability — 85/100

What we measured

No Content-Security-Policy and no HSTS.
Served over HTTPS with a valid certificate.
Real Lighthouse performance run — 277 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: sitemap, OpenGraph image, canonical URL.

Who it's for

Developers · Researchers · Nonprofit power users · Data teams · Analysts

Pricing

Free tier available; Basic $49/month; Pro $99/month

Sources and updates

Description: Taken from developers.501see.app's own website on 2026-08-26.
Operator: 501see, as named in developers.501see.app'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 2026-09-27.

Put together from public information, without 501see's involvement. If anything here is wrong, tell us and a person will check it.

Visit 501see → · Alternatives to 501see → · How this was measured →