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301 redirect (HTTP 301 Moved Permanently) A 301 redirect is the HTTP response stating that an address has moved permanently to another address; the browser takes the visitor to the new address, and the search engine learns the new address as the main address. Site migration
302 redirect (HTTP 302 Found) A 302 redirect is the HTTP response stating that an address’s content is temporarily served at another address and that the old address remains valid; the visitor goes to the new address, but the search engine gets no strong reason to let go of the old one. Site migration
What is 302 redirect (HTTP 302 Found)?
A 302 redirect is the HTTP response stating that an address’s content is temporarily served at another address and that the old address remains valid; the visitor goes to the new address, but the search engine gets no strong reason to let go of the old one.
The HTTP standard (RFC 9110) defines 302 as meaning that the resource temporarily resides at another address and that the client should keep using the original address for future requests. In other words, a 302 says “look over there for now”, not “I have moved there”. It has two siblings in the same family: 303 shows the result of an action at another address, and 307 is the method-preserving version of 302 — with a 302 the browser may turn a form submission into an ordinary page request on the next request, with a 307 it may not.
Google’s documentation classifies 302, 303 and 307 as temporary redirects: Googlebot follows the redirect but treats it only as a weak signal that the target is the main address. Where a 302 is used correctly, that is exactly what you want: sending a page to a temporary notice during maintenance, redirecting a time-limited campaign, showing another page for a while in place of a page that will come back.
Where it is used wrongly is a site redesign. If a permanent move is done with a 302, the new address being treated as the main address rests on a weak signal. This mistake usually comes not from a deliberate choice but from a default: Apache’s Redirect directive, Nginx’s return line and Cloudflare’s _redirects file send a 302 when no code is written. That is why writing out the code explicitly in a permanent move is not a detail; the 301 redirect guide gives the right line for each environment, and a criterion-by-criterion comparison of the two codes is on the 301 vs. 302 page.
- A page that will come back → 302 or 307.
- Permanent move, new site, new domain, switch to HTTPS → 301 or 308.
- A form or application call is being redirected → the method-preserving 307 or 308.
- A delayed refresh within the page → Google counts it as a temporary redirect.
We read this site’s server code: there is no 302 in it. The only temporary redirect we measured on the live site comes from the hosting platform: addresses without a trailing slash and addresses ending in /index.html are gathered onto the trailing-slash address with a 307. The code is temporary, but the destination page declares itself canonical; because the redirect and the canonical tag point to the same address, the two do not contradict each other. In the redesign and migration map for a client site, by contrast, every permanent line is written as a 301, and the code is tested separately on launch day.
If you don’t want to lose traffic while relaunching your site, website redesign and migration inventories the old addresses, builds a chain-free 301 map and monitors the site for 90 days after the move.
Site migration
A
Accessibility overlay An accessibility overlay is software added to a website through a one-line third-party script that, after the page loads, aims to cover up accessibility problems either with a user toolbar or by trying to repair the code automatically. Accessibility
Accessibility statement An accessibility statement is the text in which an organization publicly discloses, for its website or mobile app, the accessibility standard it follows, its conformance status, the content that is not accessible and the way users can report problems. Accessibility
Accessibility tree The accessibility tree is the structure a browser derives from a page and presents to assistive technology; it is the page a screen reader sees. Accessibility
Accessible name The accessible name is the name of an interface element as read by assistive technology, and it can differ from the text shown on screen. Accessibility
AEO (Answer Engine Optimization) is the practice of getting content selected as the unit that answers a question directly. Answer engines
AI Overviews is the AI-generated summary Google shows above the search results page, synthesised from more than one source. Answer engines
ARIA (Accessible Rich Internet Applications) is a set of attributes used to convey role, state and property information to assistive technology where HTML cannot express it on its own. Accessibility
B
Brand mention A brand mention is a brand’s name being named without a link, and in the era of answer engines it is a visibility signal independent of links. Answer engines
C
Cache header A cache header is the server response header that tells the browser how long a resource may be stored and how it is to be revalidated. Performance
Canonical address A canonical address is the markup declaring which page is the original when the same or very similar content is reachable from more than one address. Multilingual
Citation A citation is an answer engine mentioning a source in the answer it produces, usually with a link to it. Answer engines
CLS (Cumulative Layout Shift) measures how much content shifts unexpectedly while a page is loading or in use, and Google counts anything under 0.1 as good. Performance
Colour blindness is the inability to tell certain colours apart, and it affects a considerable share of the world’s population, men in particular. Accessibility
Compression is the shrinking of text-based resources before they are sent from the server and their expansion in the browser. Performance
Core Web Vitals is the collective name for the three metrics Google defined to measure a page’s real user experience. Performance
Country domain (ccTLD) A country domain is a two-letter top-level domain extension allocated to a particular country. Multilingual
Crawl budget is the number of requests a search engine allocates to fetching from a site within a given period. Answer engines
Critical rendering path The critical rendering path is the minimum sequence of steps a browser must complete before it can draw a page on screen. Performance
E
EN 301 549 (Accessibility requirements for ICT products and services) is the European standard, published jointly by CEN, CENELEC and ETSI, that defines the accessibility requirements for information and communication technology products and services and how they are to be tested. Accessibility
Entity An entity means a distinct thing that search and answer engines recognise — a person, an organisation, a place, a product or a concept. Answer engines
F
Field data is the sum of performance measurements experienced by real users on real devices and real networks. Performance
Focus trap A focus trap is when keyboard focus enters a region and cannot leave it again, and WCAG prohibits it explicitly at level A. Accessibility
Font subset A font subset is a font file regenerated with only the characters that are needed. Multilingual
G
GEO (Generative Engine Optimization) is the work of increasing the likelihood that a site is chosen as a source in the answers generated by AI systems. Answer engines
H
hreflang is the markup that declares a page’s different language and region versions to search engines. Multilingual
I
Index (search index) The index is the database in which a search engine keeps the pages it has decided to store out of those it crawled, and the only place it selects search results from; it is also called the search index. Being found on Google
IndexNow is an open protocol that tells search engines immediately that a page has changed. Answer engines
INP (Interaction to Next Paint) is the time from a user interaction until the page responds visually, and Google counts anything under 200 milliseconds as good. Performance
J
JSON-LD (JavaScript Object Notation for Linked Data) is a structured data format that declares a page’s meaning in a machine-readable form without changing the page’s appearance at all. Answer engines
L
Language tag (BCP 47) A language tag is the standard coding form that tells machines which language a text is in. Multilingual
LCP (Largest Contentful Paint) is the paint time of the largest content element in a page’s visible area, and Google counts anything under 2.5 seconds as good. Performance
Live region A live region is an area of a page whose changes a screen reader has to announce to the user. Accessibility
llms.txt is an optional file placed in a website’s root directory that summarises, in Markdown, what the site is about and where its most important pages are for language models. Answer engines
Locale A locale is the setting that defines a user’s language and region together and determines the formatting rules. Multilingual
Localisation (Localization) is adapting content to the culture, habits and search language of a target market; it is a wider undertaking than translation. Multilingual
N
noindex is a directive asking that a page not be added to a search engine’s index, given either with the robots meta tag inside the page or with the server’s X-Robots-Tag response header. Being found on Google
R
Redirect chain A redirect chain is when an address reaches its final address not in a single hop but by passing through more than one redirect; for example, if an old address is redirected first to an intermediate address and from there to the final address, there is a two-hop chain. Site migration
Reflow A reflow is the browser recomputing the positions and sizes of elements on a page after a change. Performance
Relative luminance is the value expressing a colour’s perceived lightness between 0 and 1, and it is the basis of the contrast ratio calculation. Accessibility
S
Screen reader A screen reader is assistive technology that turns on-screen content into speech or braille output and lets the user navigate by keyboard. Accessibility
Search Console is a free service from Google for monitoring a site’s status in Google Search and for seeing and fixing its problems. Being found on Google
Semantic HTML means choosing each element for its meaning rather than its appearance — a heading element for a heading, a button element for a button, a list element for a list. Accessibility
Sitemap A sitemap is a file, usually written in XML, that lists the addresses of a site’s pages and, optionally, their last modification dates for search engines in a single file. Being found on Google
Soft 404 A soft 404 is a page that shows visitors “page not found” or empty content but returns a 200 (success) code from the server instead of an error code; Google treats these pages as error pages and does not index them. Site migration
Structured data is an additional layer that labels a page’s content with a standard vocabulary machines can understand. Answer engines
T
Text expansion is the same content being of different lengths in different languages, and the layout having to flex accordingly. Multilingual
Translation memory A translation memory is a database that stores previously translated sentences and suggests them when the same or a similar sentence comes up again. Multilingual
TTFB (Time to First Byte) is the time between the browser sending a request and receiving the first byte from the server. Performance
U
URL inventory A URL inventory is a single list that gathers every address of a site that search engines know — current pages, address variants and old addresses; in a site redesign or migration, the redirect map is derived from this list. Site migration
W
WCAG (Web Content Accessibility Guidelines) is the international standard published by the W3C that defines the accessibility of web content through testable success criteria. Accessibility
X
x-default is a special hreflang value declaring the default page to show when no language version matches the user’s language. Multilingual