---
name: Error page
slug: error-page
category: pattern
status: published
created: 2026-08-28T00:00:00.000Z
modified: 2026-08-28T00:00:00.000Z
definition: "The whole screen a site serves instead of the page that was asked
  for: what happened, in the reader's words, and the shortest way back to
  something that works."
aliases:
  - name: 404 page
    source: community
  - name: page not found
    source: govuk
  - name: not found page
    source: community
  - name: error screen
    source: community
  - name: 500 page
    source: community
  - name: server error page
    source: community
tags:
  - content-design
  - errors
relations:
  contrastWith:
    - error-message
    - error-summary
    - no-results-state
  variantOf: []
  partOf: []
  seeAlso: []
implementations: []
sources:
  - title: "Nielsen Norman Group: Improving the dreaded 404 error message"
    url: https://www.nngroup.com/articles/improving-dreaded-404-error-message/
  - title: "GOV.UK Design System: Page not found pages"
    url: https://design-system.service.gov.uk/patterns/page-not-found-pages/
  - title: "GOV.UK Design System: Problem with the service pages"
    url: https://design-system.service.gov.uk/patterns/problem-with-the-service-pages/
  - title: "MDN: HTTP 404 Not Found"
    url: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/404
demo: inline
exhibit: false
useWhen: the requested page cannot be served at all, not one field failing
---

An error page is not a component, it is a whole screen standing in for a screen that
could not be built. Two things have to happen on it and everything else is decoration:
the reader learns what happened without being told it was their fault, and they are
handed the shortest route back to something that works. A search box, one or two links
to the places most people were probably heading, and little else. The page is a dead end
by definition, so its only real job is to stop being one.

Two different failures wear this page and want opposite answers. A not-found page means
the reader asked for something that is not here, usually from an old link or a mistyped
address, and the way out is to navigate: the page says the address does not lead
anywhere and offers the search and the home page. A server error page means the site
itself is broken, the reader did nothing at all, and navigating is useless because the
next page may fail the same way. Its way out is to wait, ideally with a time to come
back and somewhere to report it, which is why the GOV.UK Design System keeps its
"problem with the service" pattern separate from its page-not-found one.

Then the disagreement, which is real and has citations on both sides. The Nielsen
Norman Group's advice, first published in 1998 and still repeated, is to mitigate total
failure with novelty: a joke, an illustration, something that makes a dead end
forgivable. The GOV.UK Design System says the opposite outright. No informal language on
a page-not-found page, no red warning text, and never print the number 404, because
someone filing a tax return did not come for a cartoon and does not know what 404 means.
Both are right about their own reader. Novelty pays where the visit is discretionary and
the stakes are low, so a magazine, a studio site or a personal project can afford
charm. It costs where the reader is transacting under obligation or under stress, and
the only kindness left is being brief and plain. The question is not taste, it is
whether your reader chose to be here.

Technically it is one page under two contracts. The status code has to be the real one,
because a friendly page served as 200 tells search engines and monitoring that the
request succeeded, and the copy has to work for a reader who has never heard of a status
code. What this word is not: an [error message](/error-message) is the line attached to
one field, an [error summary](/error-summary) is the block at the top of a form that
failed, a [no results state](/no-results-state) is a search that matched nothing inside
a page that worked perfectly, and an [empty state](/empty-state) is a container with
nothing in it yet. All four happen on a page that loaded. This one replaced the page.