Usually, keep them. For a manufacturer, a discontinued product's page can go on being searched by its part or model number long after the last one ships. If there's a true drop-in successor, move the old part number and its documents onto the successor's page, then 301 redirect to it, never to the homepage. Otherwise keep the page live and marked discontinued. The only page that should return a 404 is one with no successor of any kind that nothing at all uses.
Who still searches for a part you stopped making?
Most of the advice on this question is written for online stores, where a discontinued item is a dead end: the shopper wanted something to buy, so you send them to something similar.
Industrial part numbers outlive the product. The number is stamped on a nameplate, printed on a drawing, and listed in somebody's bill of materials or ERP. The people who type it into a search bar years later usually aren't browsing:
- A maintenance tech whose unit failed, reading the number off the old one.
- An engineer updating an assembly drawing that still calls for it.
- A purchasing buyer whose reorder just bounced back with "obsolete".
And a distributor's catalog page may still link to your spec sheet.
If your page says what replaced the part and whether the replacement fits, the next call may well come to you. If the page is gone, they may land on a distributor's listing or a competitor's cross-reference instead.
Should discontinued product pages stay, redirect or go?
There are four cases. Check them in order: the first that fits wins.
1. There's a true drop-in successor
The new part has the same fit, form and function and can be ordered without a redesign. 301 redirect the old page to the successor's page, but first move the old part number, its manual, drawings and certificates onto that page, because the installed base still needs them. The visitor should find a successor page that names the old number as the part it replaces and keeps its documents.
2. A newer model exists, but it isn't a drop-in
Dimensions, mounting, connections or ratings changed. Keep the old page live, mark it discontinued, and link to the new model, whether or not anything else still uses the page. That link is how someone holding the old number finds the new one. The visitor should find what changed, spelled out.
3. No successor, but something still uses the page
People still search its number, other sites link to it, sales or service still get asked about it, or it holds documents (specs, drawings, manuals, certificates) a customer needs. Keep it live and mark it discontinued. The visitor should find the date, any alternative, every document, and a way to ask about stock or repair.
4. Nothing uses it
None of cases 1 to 3 applies. Let it return a 404. The visitor should find a helpful 404 page with search and navigation.
Most advice already says to redirect only to a close match, without saying what close means for an engineered part. The test is fit, form and function. A near match that fails it sends the engineer to a part that looks like the answer and might not fit.
For the same reason, I wouldn't redirect a discontinued part to its category page either. It can't say whether anything on it fits, so the engineer loses the old specs and gets a list to guess from.
What does Google do with each choice?
A kept page (200). Google says a 2xx status doesn't mean the page will be indexed. A page emptied down to "this product is no longer available" risks being reported as a soft 404, which Google describes as a user-friendly "not found" message without a 404 response code. A kept page needs real content: the specs, the documents, the replacement.
A 301. Google treats a 301 as a strong signal and shows the redirect target in search results. Google's site-move guidance says to keep one "generally at least 1 year" and, from users' perspective, to consider keeping it indefinitely. Keep it indefinitely: links in distributor catalogs and old PDFs can outlast the product. If the successor is retired later, point the old redirect straight at the final page, not through a chain.
A 404 or 410. Google's crawling documentation says all 4xx errors except 429 "are treated the same": an indexed URL that returns one is removed from the index. It doesn't distinguish 404 from 410. Search Console's own help says 404s are "not necessarily a problem" when a page has been removed without a replacement.
A redirect to the homepage. In the same site-move guidance, Google says not to redirect many old URLs to one irrelevant destination such as the home page, because it can confuse users and Google may treat it as a soft 404.
How do you tell which case a page is in?
Check these before anything is deleted:
- Search Console, Performance report. Filter the report by the page's URL rather than by a query. Google leaves rare searches out of the query table but still counts them in the page's totals, so a part number typed in a few times a year still shows up. Use the longest date range; Search Console keeps about 16 months of data.
- Search Console, Links report. "Top linked pages" shows which of your pages other sites link to. Google notes it isn't a complete list, so a missing page is unconfirmed, not unlinked.
- Sales and customer service. Ask whether calls or emails about the number still come in.
- The page itself. Look for documents a customer needs: specs, drawings, manuals, certificates.
These checks only separate case 3 from case 4. Cases 1 and 2 turn on whether a successor exists, so settle that first.
With thousands of discontinued part numbers, don't decide page by page. Set the four cases once as a rule in the ERP, the PIM or the product template, decide which case each item is in from an export, and keep every kept page linked from its category or a discontinued-products index. Inside a redesign, the redirect mapping belongs in the website migration checklist, not in somebody's memory.
What should a kept discontinued page say?
Put the status above the specs, in plain words: "Discontinued in March 2025." Avoid "out of stock", which tells the buyer to wait.
Then the replacement part number, linked, with a short note on what's different. That one line tells an engineer whether they can swap it in or have to redesign around it.
Finish with a way to ask: remaining stock, last-time buys, repairs, or help choosing a replacement, routed to whoever handles them.
Does a retired service get the same treatment?
Mostly, yes. Ask the same questions, with evidence that suits a service: do past customers still need support or records from it, do other sites link to the page, and do people still search the service's name? A retired service's page, if you keep it, carries no sales message and links to any replacement. The content audit post covers the same call site-wide.
A retired page isn't clutter until you've checked who still uses it. On a manufacturing website or an industrial website, the answer may be more people than you'd expect.
