Crawl errors - 2,513 not found. Response code 404

[JamesHancocks1]

Hi,
I've just inherited a website that I'll be looking after.

I've looked in the Search Console in the Crawl errors section and discovered thousands of urls that point to non- existent pages on Desktop. There's 1,128 on Smartphone.
Some are odd and make no sense. for example:

| bdfqgnnl-z3543-qh-i39634-imbbfuceonkqrihpbptd/ |

Not sure why these have are occurring but what's the best way to deal with them to improve our SEO?

| northeast/ | 404 | 8/29/18 |
| | 2 | blog/2016/06/27/top-tips-for-getting-started-with-the-new-computing-curriculum/ | 404 | 8/10/18 |
| | 3 | eastmidlands | 404 | 8/21/18 |
| | 4 | eastmidlands/partner-schools/pingle-school/ | 404 | 8/27/18 |
| | 5 | z3540-hyhyxmw-i18967-fr/ | 404 | 8/19/18 |
| | 6 | northeast/jobs/maths-teacher-4/ | 404 | 8/24/18 |
| | 7 | qfscmpp-z3539-i967-mw/ | 404 | 8/29/18 |
| | 8 | manchester/jobs/history-teacher/ | 404 | 8/5/18 |
| | 9 | eastmidlands/jobs/geography-teacher-4/ | 404 | 8/30/18 |
| | 10 | resources | 404 | 8/26/18 |
| | 11 | blog/2016/03/01/world-book-day-how-can-you-get-your-pupils-involved/ | 404 | 8/31/18 |
| | 12 | onxhtltpudgjhs-z3548-i4967-mnwacunkyaduobb/ |

Cheers.
Thanks in advance,
James.

[Keszi]

Hi James,

First of all you need to categorize these 404 pages, some may come from website sections that were deleted in the past, and haven't been addressed. Other 404 URLs could appear through domain redirects to your website. (unfortunately, these are harder to find, process and resolve).

For the first category (when sections have been deleted, moved, etc) you will have to ask yourself which is the correct way to resolve the issue? 301 redirect to most relevant URLs? Or just 410 and let search engines know that your page are deleted, and URLs should be removed from index. Please don't start redirecting every single 404 URL to your homepage, or any irrelevant page, or you will be creating soft 404s.

Regarding the /insertgibberishurlhere type of URLs, you should check what kind of domains are redirected to your domains (I have seen domains that had this kind of 404 not found errors via massive domain redirects to a project). First of all, if this is the case, you need to ask yourself, what are you redirecting to your website. If the domains are not in your hand, you could also redirect all of these to a 410 status code url on your website.

Oh, and the obvious version: crawl your website with tools as Screaming Frog, and make sure you are not creating the 404 URLs yourself. (almost forget about this version)

Let me know, if you have further questions.

[bridget.randolph]

Istvan has given some great advice here - one other thing I would add about the gibberish URLs though: especially with the format of these, it's possible that the site may have been the victim of a hack.

Make sure you get the site scanned for malware or other hacking activity and going forward have a security expert ensure that the site is secure (especially if it's using a platform like Wordpress which is vulnerable to hackers).