This is an XPath selectors cheat sheet, which lists commonly used XPath positioning methods and CSS selectors
Test in Firefox or Chromium based browser console:
$x('/html/body')
$x('//h1')
$x('//h1')[0].innerText
$x('//a[text()="XPath"]')[0].click()
| Xpath | CSS | 
|---|---|
//h1 | 
h1 | 
//div//p | 
div p | 
//ul/li | 
ul > li | 
//ul/li/a | 
ul > li > a | 
//div/* | 
div > * | 
/ | 
:root | 
/html/body | 
:root > body | 
| Xpath | CSS | 
|---|---|
//ul/li[1] | 
ul > li:first-child | 
//ul/li[2] | 
ul > li:nth-child(2) | 
//ul/li[last()] | 
ul > li:last-child | 
//li[@id="id"][1] | 
li#id:first-child | 
//a[1] | 
a:first-child | 
//a[last()] | 
a:last-child | 
| Xpath | CSS | 
|---|---|
//*[@id="id"] | 
#id | 
//*[@class="class"] | 
.class | 
//input[@type="submit"] | 
input[type="submit"] | 
//a[@id="abc"][@for="xyz"] | 
a#abc[for="xyz"] | 
//a[@rel] | 
a[rel] | 
//a[starts-with(@href, '/')] | 
a[href^='/'] | 
//a[ends-with(@href, '.pdf')] | 
a[href$='pdf'] | 
//a[contains(@href, '://')] | 
a[href*='://'] | 
//a[contains(@rel, 'help')] | 
a[rel~='help'] | 
| Xpath | CSS | 
|---|---|
//h1/following-sibling::ul | 
h1 ~ ul | 
//h1/following-sibling::ul[1] | 
h1 + ul | 
//h1/following-sibling::[@id="id"] | 
h1 ~ #id | 
| Xpath | CSS | 
|---|---|
//ul/li/.. | 
$('ul > li').parent() | 
//li/ancestor-or-self::section | 
$('li').closest('section') | 
//a/@href | 
$('a').attr('href') | 
//span/text() | 
$('span').text() | 
| Xpath | CSS | 
|---|---|
//h1[not(@id)] | 
h1:not([id]) | 
//button[text()="Submit"] | 
Text match | 
//button[contains(text(),"Go")] | 
Text contains (substring) | 
//product[@price > 2.50] | 
Arithmetic | 
//ul[*] | 
Has children | 
//ul[li] | 
Has children (specific) | 
//a[@name or @href] | 
Or logic | 
//a                              | //div | 
Union (joins results) | 
//div[true()]
//div[@class="head"]
//div[@class="head"][@id="top"]
Restricts a nodeset only if some condition is true. They can be chained.
# Comparison
//a[@id = "xyz"]
//a[@id != "xyz"]
//a[@price > 25]
# Logic (and/or)
//div[@id="head" and position()=2]
//div[(x and y) or not(z)]
# Use them inside functions
//ul[count(li) > 2]
//ul[count(li[@class='hide']) > 0]
# Returns `<ul>` that has a `<li>` child
//ul[li]
You can use nodes inside predicates.
//a[1]                # first <a>
//a[last()]           # last <a>
//ol/li[2]            # second <li>
//ol/li[position()=2] # same as above
//ol/li[position()>1] #:not(:first-child)
Use [] with a number, or last() or position().
a[1][@href='/']
a[@href='/'][1]
Order is significant, these two are different.
//section[.//h1[@id='hi']]
This returns <section> if it has an <h1> descendant with id='hi'.
name()            # //[starts-with(name(), 'h')]
text()            # //button[text()="Submit"]
                  # //button/text()
lang(str)
namespace-uri()
count()           # //table[count(tr)=1]
position()        # //ol/li[position()=2]
contains()        # font[contains(@class,"head")]
starts-with()     # font[starts-with(@class,"head")]
ends-with()       # font[ends-with(@class,"head")]
concat(x,y)
substring(str, start, len)
substring-before("01/02", "/")  #=> 01
substring-after("01/02", "/")   #=> 02
translate()
normalize-space()
string-length()
not(expr)         # button[not(starts-with(text(),"Submit"))]
string()
number()
boolean()
//ul/li                       # ul > li
//ul/child::li                # ul > li (same)
//ul/following-sibling::li    # ul ~ li
//ul/descendant-or-self::li   # ul li
//ul/ancestor-or-self::li     # $('ul').closest('li')
// | 
ul | 
/child:: | 
li | 
| Axis | Step | Axis | Step | 
Steps of an expression are separated by /, usually used to pick child nodes. That's not always true: you can specify a
different "axis" with ::.
# both the same
//ul/li/a
//child::ul/child::li/child::a
child:: is the default axis. This makes //a/b/c work.
# both the same
# this works because `child::li` is truthy
//ul[li]
//ul[child::li]
# both the same
//ul[count(li) > 2]
//ul[count(child::li) > 2]
# both the same
//div//h4
//div/descendant-or-self::h4
// is short for the descendant-or-self:: axis.
# both the same
//ul//[last()]
//ul/descendant-or-self::[last()]
| Axis | Abbrev | Notes | 
|---|---|---|
ancestor | 
||
ancestor-or-self | 
||
attribute | 
@ | 
@href is short for attribute::href | 
child | 
div is short for child::div | 
|
descendant | 
||
descendant-or-self | 
// | 
// is short for /descendant-or-self::node()/ | 
namespace | 
||
self | 
. | 
. is short for self::node() | 
parent | 
.. | 
.. is short for parent::node() | 
following | 
||
following-sibling | 
||
preceding | 
||
preceding-sibling | 
There are other axes you can use.
//a | //span
Use | to join two expressions.
//*                 # all elements
count(//*)          # count all elements
(//h1)[1]/text()    # text of the first h1 heading
//li[span]          # find a <li> with an <span> inside it
                    # ...expands to //li[child::span]
//ul/li/..          # use .. to select a parent
//section[h1[@id='section-name']]
Finds a <section> that directly contains h1#section-name
//section[//h1[@id='section-name']]
Finds a <section> that contains h1#section-name. (Same as above, but uses descendant-or-self instead of child)
./ancestor-or-self::[@class="box"]
Works like jQuery's $().closest('.box').
//item[@price > 2*@discount]
Finds <item> and check its attributes