Are SVG parameters such as 'xmlns' and 'version' needed?

Question

In about half of the svg examples I see on the internet, the code is wrapped in plain simple <svg></svg> tags.

In the other half, the svg tags have lots of complicated attributes like this:

<svg 
  xmlns="http://www.w3.org/2000/svg" 
  version="1.1" 
  xmlns:xlink="http://www.w3.org/1999/xlink"> 

My question is: is it ok to use the simple svg tags? I've tried playing around with the complicated ones, and everything works fine at my end if I don't include them.

Answer 1

The xmlns="http://www.w3.org/2000/svg" attribute is:

• Required for image/svg+xml files. ¹
• Optional for inlined <svg>. ²

The xmlns:xlink="http://www.w3.org/1999/xlink" attribute is:

• Required for image/svg+xml files with xlink: attributes. ¹
• Optional for inlined <svg> with xlink: attributes. ²

The version="1.1" attribute is:

• Recommended to comply with image/svg+xml files standards. ³
• Apparently ignored by every user agent. ⁴
• Removed in SVG 2. ⁵

¹ Internationalized Resource Identifiers (RFC3987)
² Since HTML5
³ Extensible Markup Language (XML) 1.0
⁴ Probably until the release of further major versions.
⁵ SVG 2, W3C Candidate Recommendation, 07 August 2018