- Discover the exclusive features and key changes in Firefox 140 ESR.
- We looked at improvements to tabs, privacy, search, and resource management.
- We'll tell you how to get the most out of the new version and what the jump from ESR 128 means.
The arrival of Firefox 140 ESR It represents a significant leap forward for users and businesses that rely on the stability and continued development of this popular open source browser. With an annual update that introduces new features and improves the user experience, Firefox 140 ESR not only represents the natural evolution of the extended support branch, but It arrives loaded with significant changes in performance, customization, security and resource management.
If you want to know in detail All the news, changes, improvements and the keys to deciding whether you should updateYou've found the most comprehensive and up-to-date guide available in Spanish. Here's the detailed analysis so you don't miss a thing.
What is Firefox ESR and why is version 140 so important?
ESR stands for "Extended Support Release", an edition of Firefox aimed at those who prioritize stability and long-term support over monthly updates. It's the ideal option for businesses, educational environments, organizations, and users who want to avoid frequent changes but still enjoy an up-to-date and secure browser.
With Firefox 140, the ESR receives a year of bulk improvements, leaving behind the ESR 128 version and accumulating features that the normal channel already had available for months.
Why is Firefox 140 ESR important? Because forms the basis for the next extended support cycle, marks the end of ESR 128 and brings together a multitude of new features that transform the experience with respect to the previous cycle.
Key new features and changes in Firefox 140 ESR
Firefox 140 improvements affect daily use, administration, and security. Among the most notable changes in the new ESR cycle are:
- Unload Tab Function: You can free up memory and CPU by unloading any tab individually using the right mouse button, without having to close it. This is very useful if you have many tabs open or limited resources.
- Improved vertical tabs and resizable pinned tab area: The vertical tab bar now lets you adjust the dedicated space for pinned tabs, making them easier to access and organize.
- Quickly add custom search engines: It's now easier to add search engines to your search list, directly from the context menu of any search field on the web, or manually from your settings.
- Removal of Pocket and associated integrations: The Pocket icon and all integrated features in New Tab are disappearing following Mozilla's decision to discontinue the service.
These improvements aim to balance stability, functionality, and ease of use, especially in contexts where the browser is a professional and in-demand tool.
Other notable new features in Firefox 140
- Sidebar enabled by default: You can now more directly access bookmarks, history, or even pin extensions and AI chatbots easily from the new sidebar.
- Built-in dictionary for Arabic spell checker: Users of this language will be able to type with greater confidence and precision directly in Firefox.
- Improvements in local translation of web pages: The translation system no longer translates the entire page, but rather visible fragments, optimizing resources and streamlining the process.
- Address autofill extension for Italy, Poland, and Austria: Address autocomplete is now expanding to these European countries, improving the experience for a broader user base.
The list of technical innovations continues, especially beneficial for developers and advanced users.
Benefits for developers and administrators
Firefox 140 is ramping up its APIs and web development tools:
- Support for Service Workers in private browsing mode: Sites can now take advantage of background processes and secure private storage, including IndexedDB and the DOM Cache API, through encryption.
- CookieStore API and custom highlighting: Support has been added for new APIs such as CookieStore for managing cookies from service workers and the Custom Highlight API for customizing text highlighting.
- Improved access to Debug and Inspector panel: Search in the Inspector has been improved, now allowing you to sort results by number of matches and use new status selectors.
- New policies for companies: For example, the policy that allowed disabling PDF.js now simply redirects PDFs to the operating system, but embedded PDFs continue to work in the browser. Additionally, all Pocket-related policies are deprecated.
These improvements make Firefox 140 more versatile and secure in enterprise and web development environments.
Improvements in resource management and user experience
One of the most important points of this edition is the efficiency and customization of the browser:
- Tabs can be unloaded individually to free up memory and CPU resources. There's no need to close the tab: it simply "suspends" until you select it again, making multitasking easier and reducing power consumption.
- The extensions menu is now more flexible, grouping unpinned extensions together, allowing you to remove the icon from the main bar if you find it unnecessary.
- Sponsored stories and content in the new tab have reduced descriptive text to make the interface cleaner and less visually cluttered.
Mozilla's attention to detail aims to make Firefox increasingly lighter, faster, and more focused on the real needs of today's users.
Comparison: Jump from ESR 128 to ESR 140
Upgrading from ESR 128 to ESR 140 means receiving all the features accumulated over the last year at once. Here are some of the most significant changes ESR users will experience after the jump:
- Tab Groups and Hover Preview: A much more visual and faster organization of your open sites.
- Vertical tabs and customizable sidebar with AI access: They improve productivity and the ability to work with more information simultaneously.
- Major improvements to Reader View and the option to copy “clean” links: The browser can now remove tracking parameters from links, and the reader view has new layout and theme options.
- Touch gestures in Linux and accessibility improvements: Responding to user demand on this platform, multi-touch gestures and support for text snippets offer added convenience.
With the arrival of Firefox 140 ESR, users in organizations, educational institutions, and anyone who values stability will finally have access to all the benefits of the mainline branch without sacrificing the robustness and reliability that characterizes Firefox ESR.
Update and download Firefox 140 ESR
Installing and updating Firefox 140 ESR is simple and adapts to the operating system you use:
- On Windows and macOS, the update is usually automatic, although you can always force it from the "About Firefox" menu.
- In the case of Linux, it depends on your distribution: Ubuntu users with Firefox in snap format will receive the update in the background; Linux Mint uses Mint Update (DEB via APT); or if you prefer, you can use the universal binary available on the official Mozilla website.
- For those still on ESR 128, migration will be automatic in September 2025 with the end of support.
It's worth remembering that Firefox ESR is primarily aimed at those seeking stability and extended support, although mainstream users can also benefit if they prefer to avoid constant changes.
What about older operating systems?
The arrival of Firefox 140 ESR also means the end of support for various versions of older operating systems. Firefox 115 ESR was the last version to support Windows 7 and 8.x, as well as macOS 10.13 and 10.14. While security patches are still being provided for these versions, their end-of-life is approaching (expected for September 2025).
To continue receiving updates and improvements, it is essential to upgrade to an operating system version compatible with Firefox 140 ESR.
Differences between the standard version and the ESR
Choosing between the standard version of Firefox and the ESR depends largely on your needs:
- If you prioritize staying up-to-date with new features and monthly updates, choose the standard version.
- If, on the other hand, you value stability, fewer changes, and maximum compatibility, the ESR is your best option.
Both versions receive security patches, but only the main version continuously incorporates new features.
Firefox 140 ESR FAQ
- Does the update affect my extensions or profiles? In most cases, there are no incompatibilities, but it's always a good idea to make a backup before upgrading.
- Can I install the ESR alongside the regular version? Yes, you can have both versions on the same system, but each will maintain independent profiles and settings.
- How do I know if I'm in ESR? Go to the Help menu > About Firefox. If you see the ESR label next to the version number, you already have it installed.
Advanced technical and administration details
For enterprise or advanced management environments, Firefox 140 ESR brings new policies and relevant settings:
- AppUpdatePin policy to prevent automatic updates if a specific version is required.
- More granular control over the viewing and handling of embedded or external PDFs.
- Changes to temporary add-on management and debugging tweaks from about:debugging.
Firefox 140 ESR maintains its corporate focus without sacrificing the improvements enjoyed by standard channel users.
And for web developers, what's new?
Significant improvements have been made to API and tool compatibility: from support for aria-keyshortcuts on all systems to security improvements (such as automatic escaping of < and > characters in HTML attributes to resist mXSS attacks) and events like pointerrawupdate.
Firefox's consolidation as a development tool, along with a more robust focus on privacy and optimization, expands its possibilities for programmers and testers.
Firefox 140 ESR is A very relevant version for both companies and organizations as well as individual users Those who value continuity and security. The accumulation of improvements, the simplification of the interface, the reinforcement of privacy, and the ease of managing resources and browsing through multiple tabs make the jump from ESR 128 especially noticeable. If you still have doubts, trying it out for a couple of days is the best way to notice the differences and enjoy a browser that evolves solidly, without losing its essence and openness.
I am a technology enthusiast who has turned his "geek" interests into a profession. I have spent more than 10 years of my life using cutting-edge technology and tinkering with all kinds of programs out of pure curiosity. Now I have specialized in computer technology and video games. This is because for more than 5 years I have been writing for various websites on technology and video games, creating articles that seek to give you the information you need in a language that is understandable to everyone.
If you have any questions, my knowledge ranges from everything related to the Windows operating system as well as Android for mobile phones. And my commitment is to you, I am always willing to spend a few minutes and help you resolve any questions you may have in this internet world.