Identify the product state
Start with the buying decision, not a blanket redirect rule. A product can be temporarily unavailable, permanently discontinued while its manual and specifications remain useful, replaced by a genuinely equivalent model, or removed with no comparable successor. Those states deserve different pages. A Hong Kong shop that sends every retired item to its home page leaves a visitor who followed an old order confirmation unable to identify the item. It also risks making the response look like an error page in search. Record the product identifier, former URL, stock and ordering status, successor relationship, and customer support needs before changing any route. The same record should inform the product page, internal search, catalogue links and any structured product data. Ask what a customer expects after arriving from a bookmarked URL: recognition of the exact item, a truthful availability statement, and a clear next action.
For a temporary shortage, keep the original product page useful if the item still exists and you intend to sell it again. Say that ordering is unavailable now; give a restock route only when your team can maintain it, and avoid promising an arrival date without supplier confirmation. If price or specification may change, do not preserve an old purchase button that can complete an impossible sale. Check the page in a signed-out browser and from the site search results. Google documents an OutOfStock value for product offer availability, but structured data must describe what the visitor can actually see and buy. An out-of-stock signal is not a substitute for plain language beside the purchase control. A retailer may choose to show comparable items, but those links should identify differences rather than imply the missing item is identical.
A discontinued item may still deserve a live page. Someone may need a compatible accessory, warranty terms, an instruction sheet, or the model number for a replacement decision. Keep the page if it has substantive original information and label the item as discontinued in the visible copy. Remove or disable the order action unless you genuinely have remaining stock for sale. Where relevant, link to a current alternative with a short comparison of dimensions, connector, capacity, or another property the customer uses to judge compatibility. Google lists Discontinued as a supported offer availability value; this is a description of the offer state, not an instruction to delete the page or a promise of a search appearance. Review inventory feeds separately because a feed that still advertises the old item can contradict the page.
Choose the destination
Use a permanent redirect only when the destination answers the old visitor's question. A renamed product with unchanged identity, or a successor that the business has carefully confirmed as the effective replacement, can justify a direct redirect. Test the destination against old links from invoices, support messages, and search results: can the customer still understand what happened to the old model? A merely similar product in the same category is not automatically a replacement. If the difference affects fit or safety, retain an explanatory page and let the visitor choose. Google's crawling guidance says a page that moved or has a clear replacement can use a 301 redirect. Its redirect documentation treats permanent redirects as a signal that the target should be canonical, so the decision should be deliberate. Keep a mapping table of old and new URLs and test the actual HTTP response, not just the address shown in a browser.
If there is no useful replacement and no reason to preserve an information page, remove the URL honestly. Google says a removed page without similar replacement should return 404 or 410. The error page can still help people navigate: identify that the item is unavailable, provide site search or a relevant category, and offer contact details for a past-order question. The server must return the corresponding error status; a friendly message wrapped in 200 success is a soft 404. Do not redirect to the home page to conceal the absence. This choice is especially useful for accidental duplicate catalogue records, test products, or pages with no lasting reference value. Before removal, inspect whether customer emails, manuals or warranty links rely on the URL; if they do, a useful historical page may be better.
Consider a concrete example. A retailer sold a countertop appliance under model A. The maker stops it and introduces model B, which has a different plug and accessory coupling. The old page should say model A is discontinued and keep its manual and accessory compatibility details. A comparison link to B should explain the plug and coupling difference; a silent 301 would falsely suggest interchangeability. Meanwhile, an old URL created for a colour variant that never shipped and has no useful information can return 404 with a path to the product family. If a supplier later confirms model C is the same appliance under a new code, a direct 301 from its former URL to the current model C page may be reasonable. These are editorial decisions backed by a product record, not one automated rule applied by age.
Check customer outcomes
Build a small release checklist before making changes. Export the affected URLs and classify each one as temporarily unavailable, informative discontinued page, confirmed replacement, or removed without replacement. Have a person who knows the products approve any equivalence claim. Update visible status, purchase controls, internal links, site search and structured data from the same approved state. Then request each old URL and record the returned status, final destination and visible message in both English and Traditional Chinese. Check a few mobile pages and logged-out sessions because cached catalogue data can preserve an old buy button. The acceptance result is a visitor who can identify the item and decide what to do, plus machine-readable responses that agree with the page. A redirect count or index report alone cannot prove that outcome.
Assign an owner for future changes. A discontinued page can become misleading when the accessory stock disappears, a warranty document changes, or a previously suggested successor is itself retired. Put the review trigger in the catalogue workflow: a supplier notice, stock-state change, support complaint, or new replacement approval should reopen the URL decision. Preserve a short change note explaining why a redirect was added or a page was retained, so the next editor does not reverse it by accident. For a large catalogue, automate finding broken internal links and status mismatches, but keep product equivalence as an accountable human judgement. The practical next step is to sample ten retired URLs today and write down the answer each visitor gets; that small audit will expose whether the current rule is serving customers or merely hiding old records.
Do not confuse the address decision with a search ranking promise. A 301 tells Google that a page has moved to a clear destination, while a truthful 404 or 410 says the old resource is gone. Neither response guarantees where a catalogue appears in results, and the decision should not be based on a claim that every old page must retain its traffic. Watch customer outcomes after the change: old links in your own emails, search results shown to shoppers, support requests about compatibility, and orders for suggested alternatives. If customers repeatedly ask whether an alternative fits, improve the comparison rather than adding more automatic redirects. If an old product page receives visits for manuals, preserve and maintain that information even though sales have ended. The editorial owner can revisit the decision when evidence changes; the URL choice is a service to the customer, not a one-time search trick.
Before changing the live system
- Does the old URL explain the exact product and its current status?
- Is a proposed successor genuinely equivalent for the buyer’s use?
- Do the visible page, HTTP response and product data agree?
