--- title: "Using Chrome's Local Overrides for design and performance optimizations · Appnovation" url: "https://www.appnovation.com/insights/using-chromes-local-overrides-design-and-performance-optimizations" description: "Use Chrome DevTools Local Overrides to persist CSS, JS and DOM changes on any live site for faster design and performance testing." --- Article # Using Chrome's Local Overrides for design and performance optimizations [![](https://cdn.sanity.io/images/ey850001/production/d554cb30b50f2e0f5ec2f886c627b6f37dd65b94-68x68.png?w=68&auto=format) azvonkov azvonkov Senior Front End Developer](/people/azvonkov-azvonkov.md) Jul 17, 2018 2 min read ![Using Chrome's Local Overrides for design and performance optimizations](https://cdn.sanity.io/images/ey850001/production/a912f270ddbcf66bdf5e946d9f037e1477ed28b9-1440x600.png?w=1400&auto=format) Chrome (65) DevTools has a great new feature called **Local Overrides**. It allows overriding CSS, JS and DOM on any live site. We use DevTools to tweak styles, test layout changes right in the browser all the time. With Local Overrides, we can keep these changes even if live page reloads. Projects might have variety of dependencies that can take a while to set up. There could be a mismatch of content and images on local and live environments. Local Overrides allows you to tweak styles and test performance right on the live site. ### Enabling Local Overrides Open the **Sources** panel and select the **Overrides** tab. **Select a directory** where you want to save your changes and allow Chrome to access it. Make sure **Local Overrides** is checked. Network tab should show an indicator. You can start modifying CSS in the styles panel or through the sources panel. All changes will be saved to a local copy of a live site’s CSS. You can also see a diff of your local modifications by Opening the Changes panel (⌘ ⇧ P). ### Performance Optimizations with Local Overrides Local Overrides can also help with **Performance Optimization**. You can test loading order of scripts, update HTML and assets right in the live environments. Check out [these (opens in new window)](https://youtu.be/UOn0b5kn3jk) [short (opens in new window)](https://youtu.be/yRrrL0Mg1pM) videos by Harry Roberts and Umar Hansa. They show practical examples of how Local Overrides can help improve performance. Local Overrides allows you to update CSS, JS, and HTML of any live site in real time even if page reloads. Changes are saved in local files and override live environment. Local Overrides is great for quick style and layout tests as well as performance optimizations. [![](https://cdn.sanity.io/images/ey850001/production/d554cb30b50f2e0f5ec2f886c627b6f37dd65b94-68x68.png?w=68&auto=format) azvonkov azvonkov Senior Front End Developer · Appnovation](/people/azvonkov-azvonkov.md) ## Keep reading [![The Digital Accessibility Checklist](https://cdn.sanity.io/images/ey850001/production/78266d3cb77b8c87e0c04130e649cdf0692c068b-1200x644.jpg?w=640&auto=format)](/insights/digital-accessibility-checklist.md) Article · 3 min Apr 07, 2023 ### [The Digital Accessibility Checklist](/insights/digital-accessibility-checklist.md) Before you publish, answer these 10 questions to assess whether you have an accessibility friendly website. [Andrew Douglas](/people/andrew-douglas.md) Article [![Delivering Accessibility and Inclusivity at Scale](https://cdn.sanity.io/images/ey850001/production/cc39507ab753250ec9e0e29021ee0a87829ab792-1201x644.jpg?w=640&auto=format)](/insights/delivering-accessibility-and-inclusivity-scale.md) Article · 5 min Apr 03, 2023 ### [Delivering Accessibility and Inclusivity at Scale](/insights/delivering-accessibility-and-inclusivity-scale.md) Discover five best practices for delivering accessibility at scale, including ways you can use technology to help automate compliance and support your wider inclusivity and diversity programs. [Andrew Douglas](/people/andrew-douglas.md) Article [![What’s next? 4 questions to ask as D7 Sunsets](https://cdn.sanity.io/images/ey850001/production/a63270a810b8ac4abda1b732409a1b8ce835b059-1200x644.png?w=640&auto=format)](/insights/2022-03-whats-next-4-questions-ask-d7-sunsets.md) Article · 5 min Mar 20, 2023 ### [What’s next? 4 questions to ask as D7 Sunsets](/insights/2022-03-whats-next-4-questions-ask-d7-sunsets.md) Raw data doesn’t drive business intelligence (BI) on its own. To successfully move from Point A to Point B, you need a solid data science practice, analytics infrastructure, and complete organizational buy-in. Here, we explain how to achieve it all. [Nathan Gervais](/people/nathan-gervais.md) Article ## Get the thinking, *before everyone else.* One considered email a month. New essays, field notes from live engagements, and the occasional strong opinion. No noise.