Section galleries / Error-page reference

404s

Give a missing page a useful recovery path.

Documentation reviewed

Source review
Oct 18, 2026

Understand the resource

What it is.

404s curates error-page designs with style and interaction filters. It offers visual ideas for an edge case whose main job remains helping a visitor find the right destination.

When it is useful

A site needs a purposeful missing-page experience.

A proposed application

Put it to work.

This example illustrates a possible use. The proposed workflow and expected result are separate from the bounded checks recorded below.

Try this

Use one restrained composition with a clear explanation, a home link and relevant search or section links.

Result to aim for

A recoverable error page within the site’s identity.

Before you start

What you need.

A real 404 route and tested recovery destinations.

The practical boundaries

What to watch for.

An entertaining page still needs the correct HTTP status and accessible navigation.
Avoid effects that delay recovery or imply the visitor caused the failure.

Review record

What we could establish.

Public primary documentation reviewed. See the account-free evaluation for executed checks and remaining workflow limits.

Source coverage and runtime coverage are separate

The source-review notes describe documentation and identity. The account-free evaluation below records exactly which public interaction or local fixture was checked, what happened, and what remains untested.

Check current access, terms, licensing and data handling before using a resource with your own material.

Runtime and security evaluation

What the evaluation covers.

Bounded runtime checkedAccount-free · Oct 19, 2026

The Ente gallery detail opened with a reference image and related entries. The gallery detail returned 200, which is expected for a reference page and says nothing about Ente’s actual error response.

Methods: Public HTTP response · Public browser sample. A completed check covers the stated sample; it is not a safety certification.

Target: https://www.404s.design/
Version or capture: Unversioned public page observed on 2026-10-19
Integrity scope: sha256:4863e918d52e65049a52c81ecdcb79cf42e40680e49f9f00c8553f1baad23939 — initial HTTP 200 response body only; not whole-application integrity.

Test conditions

Chromium 155.0.8059.82, 1365×900 desktop viewport.
Separate fresh, ephemeral browser contexts for entry and interaction; no owner profile, credentials or stored session.
Only GET/HEAD network requests allowed; forms, downloads, WebSockets and service workers blocked. Some analytics endpoints also blocked.
Short bounded waits; no mobile, assistive-technology, cross-browser or performance certification.

Individual checks and observations

Public HTTP response
pass
Public HTTP response: Anonymous GET with redirects followed, response-body SHA-256 and selected security-header summaries; no cookies retained.
Observed: The standalone client received 200 at https://www.404s.design/. This establishes response delivery only.
Fresh browser entry
pass
Public browser sample: Open the catalog URL in a new anonymous Chromium context with read-only network guards and no inherited profile.
Observed: The document returned 200 and identified itself as “404s — A Curated Gallery of Creative Error Page Designs”. 50 image elements were present; no account was used.
Observed public sample or navigation
pass
Public browser sample: Follow the observed Ente link to https://www.404s.design/sites/ente.
Observed: The destination returned 200; title: “Ente”. 15 page image elements had decoded during the bounded wait. This count is not a catalog size or performance benchmark.

Security findings and boundaries

Passive inspection of the initial public document’s response headers and anonymous browser request hostnames, with read-only guards. No source exploitation, account access, dependency audit or private data.

Observed · info

Public response protections

The initial browser page used HTTPS. Its response included HSTS. An enforcing CSP response header declared frame-ancestors. X-Frame-Options was SAMEORIGIN. This records the sampled response only; meta policies, backend authorization and exploit resistance were not assessed.

Observed · info

Request surface in the anonymous visit

404s attempted requests to 11 additional hosts, including cdn.prod.website-files.com, cdn.jsdelivr.net, ajax.googleapis.com, cdnjs.cloudflare.com. Host counts include requests stopped by the test guard; they do not establish what data a service retained.

Practical advice · caution

Before using this reference

Test the real route’s HTTP status and recovery paths after designing a 404 page; an attractive screenshot does not establish either.

Practical caveats

Test the real route’s HTTP status and recovery paths after designing a 404 page; an attractive screenshot does not establish either.
An entertaining page still needs the correct HTTP status and accessible navigation.

What remains untested

No source-site missing URL was requested. Some script errors occurred in the anonymous session, so this is a bounded detail-view result, not an all-controls pass.
Results describe the observed public pages and a bounded action, not the entire product or the referenced designs.

Security limits

No authentication, authorization, tenant separation, data retention or backend handling was tested.
Header presence or absence is a sampled configuration observation, not a security certification or an exploit finding.
0 blocked-request records were retained across entry and interaction checks. Guards may alter normal page behavior; the logs do not represent unrestricted traffic.

Evaluation sources

Download this evaluation record (JSON)

Follow the evidence

Sources and further reading.

Primary resource page

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