kb/data/developer.mozilla.org/en-US/docs/Glossary/bfcache-0.md

title	chunk	source	category	tags	date_saved	instance
bfcache - Glossary | MDN	1/3	https://developer.mozilla.org/en-US/docs/Glossary/bfcache	reference	web, html, css, javascript, documentation	2026-05-05T05:50:01.435395+00:00	kb-cron

• Skip to main content
• Skip to search

MDN HTML HTML: Markup language

HTML reference

• Elements
• Global attributes
• Attributes
• See all…

HTML guides

• Responsive images
• HTML cheatsheet
• Date & time formats
• See all…

Markup languages

• SVG
• MathML
• XML

CSS CSS: Styling language

CSS reference

• Properties
• Selectors
• At-rules
• Values
• See all…

CSS guides

• Box model
• Animations
• Flexbox
• Colors
• See all…

Layout cookbook

• Column layouts
• Centering an element
• Card component
• See all…

JavaScriptJS JavaScript: Scripting language

JS reference

• Standard built-in objects
• Expressions & operators
• Statements & declarations
• Functions
• See all…

JS guides

• Control flow & error handing
• Loops and iteration
• Working with objects
• Using classes
• See all…

Web APIs Web APIs: Programming interfaces

Web API reference

• File system API
• Fetch API
• Geolocation API
• HTML DOM API
• Push API
• Service worker API
• See all…

Web API guides

• Using the Web animation API
• Using the Fetch API
• Working with the History API
• Using the Web speech API
• Using web workers

All All web technology

Technologies

• Accessibility
• HTTP
• URI
• Web extensions
• WebAssembly
• WebDriver
• See all…

Topics

• Media
• Performance
• Privacy
• Security
• Progressive web apps

Learn Learn web development

Frontend developer course

• Getting started modules
• Core modules
• MDN Curriculum
• Check out the video course from Scrimba, our partner

Learn HTML

• Structuring content with HTML module

Learn CSS

• CSS styling basics module
• CSS layout module

Learn JavaScript

• Dynamic scripting with JavaScript module

Tools Discover our tools

• Playground

• HTTP Observatory

• Border-image generator

• Border-radius generator

• Box-shadow generator

• Color format converter

• Color mixer

• Shape generator

About Get to know MDN better

• About MDN

• Advertise with us

• Community

• MDN on GitHub

Blog

1. Glossary
2. bfcache

bfcache

The back/forward cache, or bfcache , is a performance-enhancing feature available in modern browsers that enables instant back and forward navigation between previously-visited pages. It does this by storing a complete snapshot of a page as the user navigates away from it; the browser can then quickly restore the snapshot if the user decides to return to it, rather than needing to repeat the network requests required to load the page. The snapshot contains the entire page in memory, including the JavaScript heap; in-progress code is paused when the user navigates away and resumed when they return to the page. A regular HTTP cache entry on the other hand contains only responses to previous requests. The bfcache therefore provides faster results than the HTTP cache. The downside is that bfcache entries require more resources, and create complexity in terms of how to represent in-progress code. Some code features (for example the unload handler) are not compatible, so their presence on a page blocks it from using the bfcache. The bfcache is great for performance, so it is in your interests to make sure your pages are not blocked from using it. You can use the notRestoredReasons API to monitor whether pages are blocked from using the bfcache, and reasons why.

In this article

• See also

See also

• Back and forward cache on web.dev (2023)