So do I need to follow some guidelines regarding the length of an alt property?
There is no set maximum length for the value of alt tags, however, most advise for the benefit of sight impaired users to keep it under 125 characters - see this and this.
I have the same question regarding the title property.
In regards to title attributes, like with the alt text, there is no set maximum length. However, since this is used for tooltip text for an element, usability for the visually impaired should also be considered as the W3 covers here, suggesting that the 125 character size would similar apply. You may also find through browser compatibility testing, that the tooltip will get cutoff after a certain length, varying by browser.
Since title property might also refer to title element, search engines like Google will truncate your title element, or even compose their own based on your content, if it's too long. As suggested here by MOZ, the goal should be to keep it to under 70 characters or less:
Answer from dan on Stack ExchangeTitle Tag: Best Practices for Length
Aim for title tags containing fewer than 70 characters. This is the limit Google displays in search results. Title tags longer than 70 characters may be truncated in the results, or search engines may choose to display different text from the document in place of the title tag. Recent experiments have shown that the number of characters displayed in the search results may also vary based on—among other things—the width in pixels of each letter. 70 characters is still a good general guideline for length, though.
seo - Are there any length limitations for image alt or title property? - Webmasters Stack Exchange
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Max length on title tags for SEO
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So do I need to follow some guidelines regarding the length of an alt property?
There is no set maximum length for the value of alt tags, however, most advise for the benefit of sight impaired users to keep it under 125 characters - see this and this.
I have the same question regarding the title property.
In regards to title attributes, like with the alt text, there is no set maximum length. However, since this is used for tooltip text for an element, usability for the visually impaired should also be considered as the W3 covers here, suggesting that the 125 character size would similar apply. You may also find through browser compatibility testing, that the tooltip will get cutoff after a certain length, varying by browser.
Since title property might also refer to title element, search engines like Google will truncate your title element, or even compose their own based on your content, if it's too long. As suggested here by MOZ, the goal should be to keep it to under 70 characters or less:
Title Tag: Best Practices for Length
Aim for title tags containing fewer than 70 characters. This is the limit Google displays in search results. Title tags longer than 70 characters may be truncated in the results, or search engines may choose to display different text from the document in place of the title tag. Recent experiments have shown that the number of characters displayed in the search results may also vary based on—among other things—the width in pixels of each letter. 70 characters is still a good general guideline for length, though.
The alt attribute's SEO value is minimal to begin with. You can also be sure that, like page titles, anchor text, etc, at some point search engines stop reading that content and/or devalue it.
Alt attributes are supposed to be short and descriptive so it sounds like you are misusing that attribute. You probably should be using the longdesc attribute instead which allows for more verbose content.
Hello, everyone.
I am getting back into SEO and was wondering with all the recent SEO changes, especially with Google and their ranking factors, when creating a website and optimizing title tags, what is the total length of title tags with the new SEO ranking factors? I cannot seem to find the information in the Google Search Central documentation (formally known as Google Webmaster Guidelines). Thanks for your responses.