Update: In May 2016 Google changed the limit from 512 pixels to 600.
I analysed 786,031 search result titles that I had hanging around to find out how much of a page title can get displayed. Is it based on characters, pixels or something else?
All the titles are taken from search results provided in Australia during December 2012. They cover a range of large and small markets that I work in. I removed duplicates then processed each title to work out the number of characters in them, as well as how many pixels wide they are (including spaces but excluding the ending ellipses).
It's known that Google crops titles around complete words. This can help explain why we get the spike before the cut-off point as titles are cropped more than they have to be to keep complete words.
There were a few titles that broke the mould and had lengths up to 168 characters. A large proportion of the long ones were related to Google Books so I tracked one down to see what was happening. And it ended up being hidden text!
It seems the title generator for Google Books does not follow the rules. This combined with a CSS style to crop the text and we get this funny looking result. If I disable the CSS cropping (overflow: hidden) you can see the full text:
Looks like the Books department needs a heads up!
The cropping style looks like it is applied to all results. This means titles will get automatically cropped and ellipsed if they exceed 512 pixels. No mater what! Which leads nicely onto analysing pixel widths of the titles:
SERP Title Character Count
I first heard about the idea of titles limited by pixels from SEO mofo - the world's greatest seo (Self proclaimed). And I think there is something in it.
This graph seems to have a sharper cut-off at around 500 pixels. Interestingly, ellipses take up 12 pixels bringing us to the 512 pixel forced by the CSS cropping noticed above.
Possible Conclusion: The title length limit is 512 pixels and you lose 12 pixels for the ellipses if you get cropped. This equates to around 70 characters.
No matter what, you can never see more than 512 pixels of the title as it gets cropped by CSS.
I've changed two titles on my website so their lengths are 512 and 513 pixels respectively. I hope the first shows full while the second is cropped.
My Google Search Result Emulator will help you preview your search results based on this 512px limit.
What do you think?