Should I use XPath or CSS selectors for web scraping?
Both XPath and CSS selectors have their place in web scraping. Understanding when to use each is key.
CSS selectors advantages:
- Simpler, more readable syntax
- Faster for most selections
- More familiar to web developers
- Supported by all modern scraping libraries
- Better for structure-based selection
XPath advantages:
- Can navigate up the DOM tree (parent selection)
- Can select based on text content
- More powerful for complex conditions
- Can access attributes more flexibly
- Better for XML documents
When to use CSS selectors:
Structure-based selection:
div.product > h2.title
Class and ID matching:
.product-card #price
Simple hierarchies:
ul.menu li a
When to use XPath:
Text-based selection:
//button[contains(text(), "Add to Cart")]
//h2[text()="Product Details"]
Parent navigation:
//span[@class='price']/parent::div
//a[text()='Details']/../..
Complex conditions:
//div[@class='product' and @data-available='true']
//input[@type='text' or @type='email']
Attribute contains:
//img[contains(@src, 'product')]
//div[starts-with(@class, 'item-')]
Performance comparison:
For most selections:
- CSS: 10-20% faster
- XPath: Slightly slower but negligible for small documents
Best practice:
- Use CSS selectors for 80-90% of tasks
- Use XPath when you need text matching or parent navigation
- Don't mix unnecessarily - stay consistent
Example: When XPath is better:
Finding a price next to specific text:
//td[text()='Price:']/following-sibling::td
This is very difficult with CSS selectors.
Recommendation:
Start with CSS selectors (simpler, faster). Switch to XPath only when CSS can't handle your requirement, specifically for:
- Text-based selection
- Parent/ancestor navigation
- Complex predicates