The document outlines best practices for successfully migrating a website, emphasizing the importance of thorough preparation, testing, and documentation. It highlights the need to assess current site health, establish a clear migration strategy, and monitor performance post-migration to avoid common pitfalls. It stresses the significance of proper redirect handling and ongoing keyword ranking checks to maintain SEO integrity during the migration process.

1. Bastian Grimm, Peak Ace AG | @basgr
Successfully relaunching your website // The tech edition
Migration Best Practices

2. Get well soon, Theresa!
I am just the replacement…

3. #1 Never change a running system!

4. pa.ag@peakaceag4
Every (big) change brings (loads of) opportunity!
But always keep in mind: the price tag for failure is immense!
Risk Reward
User acceptance “Once in a lifetime” opportunity
Project complexity Greenfield project: question everything
Resilience/freeze Best chance to really “get shit done”
Interruption Opportunity to eliminate “legacy problems”
Politics Usually more agile vs regular, daily business
Performance Rethink RWD/dynamic serving, HTTPS, URL design, etc.

5. pa.ag@peakaceag5
What is your goal for the migration?
The right mindset is super, super important!
I want to lose as little as
possible!” – isn’t really the
right goal for a migration!

6. Thorough documentation, in-depth definition of requirements
and ongoing testing are essential!
Be crazy about details

7. …from someone who has successfully
done this type of work before.
Ask for help…

8. #2 A lot of preparation

9. What should go, what can stay? Complete vs partial site move?
Define your migration strategy

10. pa.ag@peakaceag10
Pre-migration site health check & clean-up
A properly optimised domain migrates easier and more efficiently.
Getting your house in order before the move minimises the risk of losing rankings.
▪ Google Search Console: manual actions,
server errors (DNS, 5XX response codes),
mark-up validation errors (AMP, schema.org,
rich cards), robots.txt
▪ Web crawl: internal redirects as well as
redirect chains, broken URLs, and internal links
▪ Log files: broken URLs, suspicious status
codes, crawler traps
▪ Algo issues? Relocating with Panda,
Penguin & Co. makes very little sense

11. pa.ag@peakaceag11
You will need an arsenal of tools!
A lot depends on personal taste, but you’ll need at least one tool each for crawling, log
file analysis as well as search intelligence – and yes, this costs money!

12. pa.ag@peakaceag12
At a minimum: fix broken pages & broken internal linking

13. Figure out well in advance how to get access to all relevant server
access logs, e.g., native access or using a SaaS solution.
Get access to server logs

14. pa.ag@peakaceag14
Gather all URLs including static assets #1
Must haves: log files, XML sitemaps as well as a full website crawl
Extras: analytics (top ranking URLs and/or URLs generating the most traffic)
Mode > List > Upload
small domains
large domains

15. pa.ag@peakaceag15
Gather all URLs including static assets #2
Additionally: get the URLs that are strongly linked, bring a lot of traffic and/or have
been shared the most, etc.

16. pa.ag@peakaceag16
Switch to monitor your keyword rankings daily
Check critical keywords daily to ensure you are only working with the most recent data.

17. pa.ag@peakaceag17
Establishing a status quo performance benchmark
Lighthouse (via Chrome DevTools) or webpagetest.org provide relevant metrics.
Important: don’t just test the homepage, but also category/product pages.

18. As a rule of thumb: 1-to-1 redirects from old to new!
Prepare URL redirect mapping

19. pa.ag@peakaceag19
Provide staging/test server
Make sure the server is locked-down properly to ensure your content doesn’t get
indexed in advance (i.a. duplicate content problems).
Methodology Pros Cons
noindex (meta tag/header)
▪ External tools can access without
separate access rules
▪ URLs are definitely not indexed
▪ Indexing rules cannot fully be tested
(all noindex)
▪ Waste of crawl budget
robots.txt
▪ External tools can access without
separate access rules
▪ No crawl budget is wasted
▪ Indexing rules cannot fully be tested
(only with robots.txt override)
▪ If linked, test URLs may appear in the index
(without title/metas).
password secured (.htaccess)
▪ No crawl budget is wasted
▪ URLs are definitely not indexed
▪ Everything can be tested properly
▪ External tools must be able to handle
password authentication.
IP-based access
▪ No crawl budget is wasted
▪ URLs are definitely not indexed
▪ Everything can be tested properly
▪ External tools must be able to handle IP-based
authentication.
VPN ▪ Absolutely safe! ▪ So safe, only a few tools can handle it!

20. #3 Implement necessary changes

21. pa.ag@peakaceag21
Migration types and their potential impact on SEO
Often these types overlap – or multiple things are done at once.
Inspired by @jonoalderson: http://pa.ag/2xUCMnJ
Type Example
Hosting migrations You’re changing hosting or CDN provider(s).
You’re changing, adding, or removing server locations.
You’re changing your tech stack/caching/lbs.
Software migrations You’re changing CMS (or its version/plugins, etc.).
You’re changing the language used to render the website.
You’re merging platforms; e.g., a blog which operated on a separate domain.
Domain migrations You’re changing the main domain of your website.
You’re buying/adding new domains/subdomains to your ecosystem.
You’re moving a website, or part of a website, between domains.
Template migrations You’re changing the layout/structure/navigation of important pages.
You’re adding or removing template components.
You’re changing elements in your code, like title, canonical, or hreflang tags.
… and there are more:
▪ design migrations
▪ strategy migrations
▪ content migrations
▪ protocol migrations
▪ etc.

22. pa.ag@peakaceag22
Make it a granular, multi-step approach
Doing everything at once will make debugging & rolling back an almost impossible
task!
Source: http://pa.ag/2yJqT1N

23. pa.ag@peakaceag23
Build your very own migration Q&A check-list
Depending on what type of changes you’re undergoing, this needs to be adapted.
Use Aleyda’s template for more inspiration: https://pa.ag/2H6bOLH
Canonical tags & other rel-alternate annotations
Remember to annotate your dedicated mobile site and
to adapt your RSS feeds
Stage: Pre-migration Who? Bastian When? 23.05.18
Multilingual setup: customise hreflang target URLs
Keep in mind: Various locations can be affected
(e.g. head section, server headers, xml sitemaps)
Stage: Pre-migration Who? Bastian When? 23.05.18
Update pel=next/prev pagination annotations
Are you using Google´s recommendation for pagination?
Stage: Pre-migration Who? Bastian When? 23.05.18
Update XML sitemaps
Sitemap index file needs to be changed also,
if you reference it in robots.txt
Stage: Pre-migration Who? Bastian When? 23.05.18
Structured data update (schema.org)
Update your schema.org mark-up references.
Short annotations like “//schema.org“ don´t validate!
Stage: Pre-migration Who? Bastian When? 23.05.18
Update CDN settings and resource hints
Update requests for assets to CDNs & any resource hints
(preconnect, dns-prefetch)
Stage: Pre-migration Who? Bastian When? 23.05.18
Update HTTP header & customise cookie settings
If applicable, customise X-Robots header tags.
Use Chrome DevTools!
Stage: Pre-migration Who? Bastian When? 23.05.18

24. pa.ag@peakaceag24
Update internal links
Simply relying on redirects is no migration strategy.
Links to other internal URLs Links to internal video filesLinks to internal JavaScript files
JS
HTML
Source code
Links to internal image files Links to internal CSS files Links to internal web fonts

25. pa.ag@peakaceag25
Update internal links (within JavaScript files)
Simply relying on redirects is no migration strategy.
JAVASCRIPT
Files
Links to other internal URLs Links to internal image files Links to internal CSS files

26. pa.ag@peakaceag26
Update internal links (within CSS files)
Simply relying on redirects is no migration strategy.
CSS
Files
Links to internal web fontsLinks to internal image files
Links to other internal URLs

27. pa.ag@peakaceag27
Be careful with internal redirects!
Avoid redirect chains: old URLs should lead directly to the corresponding new URL.
Source: Redirect Chain Report via DeepCrawl

28. pa.ag@peakaceag28
Tricky: don‘t miss “invisible“ HTTP headers!
If in use: update X-Robots header tags accordingly. Use Chrome Dev. Tools to visualise!
X-Robots rel-canonical using Apaches‘ .htaccess
<Files theRequestedFile.pdf >
Header add Link 'https://www.example.com/ebook.html; rel="canonical"'
</Files>
Other HTTP header variants:
▪ Link: <https://www.example.com/de/>; rel="alternate"; hreflang="de"
▪ Link: <https://www.example.com/someurl>; rel="canonical"
▪ Link: <https://cdn.example.com>; rel="dns-prefetch"

29. pa.ag@peakaceag29
Everything updated? Side-by-side comparison crawl!
Better safe than sorry: let’s test crawl the staging server and run a comparison to make
sure all contents are 1:1 available:

30. #4 Work your search console

31. pa.ag@peakaceag31
Create new properties & eventually merge them into a set
For example, properties for HTTP and HTTPS with and without www = four domains
If you use separate mobile domains, there are six domains in total!
Prerequisites for a migration:
▪ No manual actions
▪ No significant amount of crawl errors (DNS,
availability)
▪ No problems with the XML sitemaps
▪ Valid structured data/rich cards markup, no AMP
and hreflang errors

32. pa.ag@peakaceag32
Transfer disavow links file in time
Especially for domains with a “questionable” link profile: GSC setup and disavow file
transfer should be done approximately 48 hours before going live!

33. pa.ag@peakaceag33
Set your preferred domain and (if necessary) crawl rate
You don’t need to set the crawl rate, but, if you have done so previously, I would
suggest transferring the original settings (for now).

34. pa.ag@peakaceag34
Configure geo targeting for gTLDs
Synchronise settings for handling URL parameters if necessary (i.e. for “.com” gTLDs).

35. pa.ag@peakaceag35
Before you send to the index: test GSCs fetch & render
Make sure Google includes and displays all requested components properly!

36. pa.ag@peakaceag36
Test and re-submit all XML sitemaps
Also: synchronise URL parameter settings, if you were using them or if you need them
for your site’s functionality.

37. After all this preparation, all you need to do now
is to "just" redirect URLs.
301 redirects all the things!

38. pa.ag@peakaceag38
Even if, as some Googlers say, all redirects are equal…
…all we did for this client was change the (chained) 302/307 to 301 redirects!

39. Note: it only works for domain migrations!
Use the GSC “site move” feature

40. e.g. domain.at to domain.com/at/ won‘t work!
The destination can‘t be a gTLD folder!

41. pa.ag@peakaceag41
List crawl of old URLs & manual SERP checks
Import old URLs, e.g., to ScreamingFrog (list mode), only 301s should appear here.
Additional manual check of indexed URLs, e.g., via LinkClump add-on in Chrome.
1
2
3
4

42. The most common problem with migrations gone wrong?
Missing or wrong redirects!
Seriously: check your redirects

43. #5 Post migration to-do‘s

44. Focus on 4XX and 5XX status codes first, tackle those “live”!
Log file, GSC & GA error monitoring

45. Re-test: no broken URLs (4/5XXer), tracking in place,
correct metadata & other tags, indexing rules, etc.
Complete crawl of the new domain

46. pa.ag@peakaceag46
#1 Migration performance monitoring
HTTP error status code monitoring (e.g., 40X for Googlebot & Bingbot)

47. pa.ag@peakaceag47
#2 Migration performance monitoring
HTTP redirects over time and split by user agent containing *bot*

48. pa.ag@peakaceag48
#3 Migration performance monitoring
Top crawled pages breakdown (daily & weekly)

49. pa.ag@peakaceag49
All you need to know about log file auditing
In case you just missed my session, here are the slides:
More on SlideShare: https://pa.ag/seok18logs

50. pa.ag@peakaceag50
Test and apply an “if... then... logic”
Based on your previously built Q&A checklist, make sure to double-check everything!
IF
you work internationally, then test
hreflang tags/sitemap annotations. IF
PPC ads are shown, then update and test
the landing page URLs.
IF
Google news listings are available,
then test the Google news sitemap. IF
ratings (featured snippets) are available,
then test schema.org mark-up.
IF
SSL is also used on other subdomains,
then test these as well.
etc.

51. pa.ag@peakaceag51
AMP, structured data, and rich cards error monitoring

52. Google needs to recrawl ALL the relations, that takes time!
Consider hreflang to be broken

53. Short-term peaks are completely normal, dramatic drops rather not!
Keep an eye on the crawl frequency

54. pa.ag@peakaceag54
Compare performances side-by-side
HTTPs is usually a little bit slower (handshake etc.): compare your results.
Clear goal: never slower than before (always use HTTP/2 when switching to HTTPs)
Try it out: https://www.webpagetest.org/

55. pa.ag@peakaceag55
Adjusting/revising external linking
Not every link source needs to be updated; focus on the strongest domains (e.g. via
LRT Power*Trust or Majestic Trust Flow).
Source: Majestic

56. Re-crawling, recalculation & the inheritance of
„trust“ may take a few weeks…
First and foremost: be patient!

57. pa.ag@peakaceag57
Especially for new URLs, two weeks are not enough:
Source: http://pa.ag/2htz26D
[…] it can take two
weeks for some sites
but for larger sites,
it is more like three
months, not even
close to two weeks.

58. #6 Some tips to make your life easier

59. pa.ag@peakaceag59
#1 Bulk testing all the things: mobile-friendliness
Mobile-friendliness at scale: technicalseo.com
Check it out: https://technicalseo.com/seo-tools/mobile-friendly/

60. pa.ag@peakaceag60
#2 Bulk testing all the things: hreflang tags
Hreflang tags (in sitemaps) at scale: technicalseo.com
Check it out: https://technicalseo.com/seo-tools/hreflang/

61. pa.ag@peakaceag61
#3 Bulk testing all the things: redirects & other headers
HTTP status codes (errors, redirects, etc.) at scale: httpstatus.io
Check it out: https://httpstatus.io/

62. pa.ag@peakaceag62
#4 Simulate Googlebot for smartphones with JS-rendering
ScreamingFrog can do that easily at scale; pay close attention to rendered output!
Also pretty cool: Extract > Xpath > //head/link[@rel="amphtml"]/@href

63. pa.ag@peakaceag63
#5 Don’t forget to redirect your images as well!
When changing URLs/domains, make sure to implement redirect rules for images.
Read the entire post: http://pa.ag/2yJtTLz

64. pa.ag@peakaceag64
#6 Move your robots.txt file
When changing domains, make sure to transfer (the contents of) robots.txt!

65. pa.ag@peakaceag65
#7 HTTP 503 is your friend
Combine with “revisit-after” to throttle crawling; never use “noindex”/4XX instead!
Source: http://pa.ag/2xRiA5T
Webmasters should return a 503 HTTP header for all
the URLs participating in the blackout […] Googlebot's
crawling rate will drop when it sees a spike in 503 […]
as Googlebot is currently configured, it will halt all
crawling of the site if the site’s robots.txt file returns a
503 status code for robots.txt.”

66. pa.ag@peakaceag66
#8 GSC’s DNS verification can be pretty helpful
No need to worry about missing meta tags; plus you can verify before deploying a
site/frontend to a new domain – and it’s faster as well!
More: http://pa.ag/2yJ7xtH

67. pa.ag@peakaceag67
#9 Fix those redirect chains, especially on legacy sites…
…as multiple requests waste valuable performance and crawl budget!

68. pa.ag@peakaceag68
#10 Careful: JavaScript frameworks are still tricky
Check out Bartosz‘ massive research on crawlability and indexability!
Read more: http://pa.ag/2qLqlqH

69. pa.ag@peakaceag69
So in a nutshell…
Whenever you perform migrations, make sure to:
01
Don‘t migrate
legacy!
Do a thorough health
check and clean-up
first – it‘ll be super
hard to analyse errors
later on.
02
Collect all the data
necessary in advance!
Make sure to fully
understand your URL
portfolio, crawl & GSC
data etc.
03
Get access to server
log files!
As much as I love
GSC, the data comes
in delayed – and you
need instant feedback
on errors, etc.
04
Check your
redirects, at least
twice!
Make sure to review
your redirect
mappings multiple
times, ideally with
another set of eyes.
05
Be patient & don‘t
panic!
Don‘t freak out,
seriously. Sometimes
things can just take a
bit longer for Google
to fully process (and
to pass along signals).

70. pa.ag@peakaceag70
We’re hiring! 30+ performance marketing jobs in Berlin!
Come and say “hello” or apply via jobs.pa.ag. We look forward to talking to you!
Always looking for talent!
Check out jobs.pa.ag

71. twitter.com/peakaceag
facebook.com/peakaceag
www.pa.ag
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WINNER
Bastian Grimm
bg@pa.ag
Slides? No problem:
https://pa.ag/seok18mig
You want our migration checklist?
e-mail us > seokomm@pa.ag