Shopify Javascript deferral apps 2025

Thunder Page Speed Optimizer

$19.99-$39.99 / Month

9.1

97 Reviews

Pagespeed & slow apps optimizer, speed booster, images, SEO Show more

Thunder Page Speed Optimizer is a revolutionary app designed to eliminate slow loading times and enhance website performance with just one click. By fully automating the optimization process, Thunder takes care of all elements that could potentially slow down your website, such as apps, images, and themes, without requiring any manual intervention. This powerful tool ensures your theme is lightning-fast, significantly boosting your Google Page Speed Score. Thunder's advanced features include instant "above the fold" loading and predictive preloading webpage technology, ensuring a seamless browsing experience for your visitors. Additionally, it employs image compression, lazy loading, and deferral of non-essential JavaScript code to further enhance performance. With Thunder, you can reduce customer frustration, increase conversion rates, and improve SEO, making it an essential tool for any online store owner looking to maximize their website's potential.

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Image compression

Seo enhancement

Speed booster

Automated optimization

Predictive preloading

Fix slow apps

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Hyperspeed EXTREME Page Speed

$49 / Month

9.1

238 Reviews

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Accelerate sales and improve SEO with our Page Speed optimizer Show more

Hyperspeed: Extreme Page Speed is an innovative app designed to transform the user experience of your online store by dramatically improving its loading times. It leverages advanced PageSpeed optimization techniques, ensuring your mobile and desktop sites operate at peak efficiency, keeping customers engaged and reducing bounce rates. The app enhances your store's Core Web Vitals, essential for maintaining strong SEO performance and converting traffic into sales. It offers a suite of optimization tools, including LazyLoad, critical CSS, JS deferral, and minification, to streamline your website and make it faster than ever. Hyperspeed also incorporates SEO features such as image compression, theme optimization, and automated performance monitoring to proactively maintain optimal store speed. By reducing the impact of third-party Shopify apps and offering unlimited image adjustments, Hyperspeed helps create a smoother, more enjoyable shopping experience for your customers. Start using Hyperspeed today to unlock the full potential of your store's speed and overall performance.

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Image compression

Mobile speed boost

Desktop speed boost

Lazyload

Critical css

Minification

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JsRates: Custom Shipping Rates

$35 / Month

9.1

14 Reviews

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Create custom shipping rates using JavaScript. Show more

JsRates: Custom Shipping Rates is a powerful app designed to give businesses unprecedented control over their shipping calculations by allowing them to create custom shipping rates using JavaScript. This app is perfect for overcoming the limitations of inflexible, one-size-fits-all shipping solutions, catering instead to businesses with complex or varied shipping needs. With JsRates, users can craft personalized shipping rules by leveraging third-party APIs, distance metrics, zip/post codes, and more. It also supports the integration of data from spreadsheets such as Google Sheets, CSV, and Excel to set up intricate shipping rate structures. The app is Shopify Plus friendly and includes a dedicated API endpoint, allowing seamless integration of rates into product and cart pages. To help businesses optimize their shipping strategy, JsRates offers personalized guidance and support in configuring shipping rates, making it a versatile tool for addressing any shipping challenge.

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Custom shipping rates

Javascript integration

Spreadsheet integration

Real-time plugins

Api endpoint

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MinifyMe ‑ File Optimizer

(2.7/5)

17 Reviews

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Minify CSS, JavaScript & Liquid files to speed up your store Show more

MinifyMe - File Optimizer is an intuitive app designed to enhance your store's performance by efficiently optimizing theme assets. With no developer experience required, users can effortlessly reduce the size of JavaScript, Liquid, and CSS files, leading to improved site speed and performance. The app simplifies file optimization with a user-friendly interface, allowing anyone to minify their files with just the press of a button. One of its standout features is the ability to easily revert minified files, enabling users to make necessary edits or fixes before reapplying the optimization. MinifyMe ensures a seamless and accessible experience for users aiming to boost their site's efficiency. Whether you're a seasoned professional or a novice, achieving a faster, more responsive store has never been easier.

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Shopify admin integration

Improve site speed

Minify css files

Minify javascript files

Minify liquid files

Easy file revert

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IBuyUPay

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Effortlessly streamline online payments with IBuyUPay. Try risk-free today!

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Iconaro ‑ Snappy Custom Icons

8.2

2 Reviews

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Fully Custom Icons & Trust Badges that keep your store snappy. Show more

Iconaro - Snappy Custom Icons is an innovative app designed to enhance your online store's aesthetic appeal and convey value to your customers. With Iconaro, you can easily add custom SVG and PNG icons to your store and customize their appearance without needing any CSS knowledge. Modify text size, color, icon size, spacing, and background styling effortlessly to suit your brand's needs. The app prioritizes performance by rendering icons without JavaScript, ensuring your site remains fast and responsive. Moreover, Iconaro is SEO-ready, supporting alt-tags for better search engine optimization of your icons. It's an accessible tool that requires no additional coding or design skills, making it easy for anyone to try and elevate their store's visual appeal.

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Custom svg/png

Modify styling easily

No javascript

Seo-ready icons

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EZ Custom HTML

$4.99 / Month

8.2

3 Reviews

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Easily add custom HTML, custom Javascript, and custom CSS Show more

EZ Custom HTML is a user-friendly app designed to simplify the process of adding custom HTML, CSS, or JavaScript to Shopify pages without the need for programming knowledge. This app serves as an App Block within Shopify's Theme Editor, allowing users to effortlessly drag and drop to place their custom code exactly where they want it. It eliminates the headache of dealing with theme liquid files, making customization accessible to all Shopify store owners. With this app, even those without JavaScript skills can enhance their store's functionality and appearance by incorporating custom scripts and styling. Users can expect first-class support, with responses typically within 24 hours, adding to the app's convenience and reliability. Whether you need to tweak the aesthetics or introduce new features, EZ Custom HTML streamlines the customization process on your Shopify store.

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Add custom html

Add custom css

Add custom javascript

Drag-and-drop functionality

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CodeUp ‑ Add Custom Code

(3/5)

2 Reviews

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Easily Insert Custom Header & Footer Code to Your Store Show more

CodeUp - Add Custom Code is a versatile application designed to enhance your website's functionality by effortlessly integrating various codes into your site. With CodeUp, you can easily add essential codes such as Google Site Verification, Facebook Domain Verification, Google Analytics, and Facebook Pixel, as well as third-party scripts and live chat scripts. It also allows for the inclusion of custom CSS, empowering you to personalize your site's appearance and performance. The app provides a user-friendly interface, making it simple to customize and manage your code placements, whether in the head or body section. CodeUp offers intuitive features like simple code customization and page-wise code loading, ensuring an efficient and streamlined experience. Enhance your website's capabilities with this powerful tool and make your web presence more impactful and professional.

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Easy to use

Simple code customization

Load code pagewise

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GDPRify ‑ Smart GDPR Banner

$3-$19 / Month

7.6

55 Reviews

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Block Cookies and JavaScript with a geo-targeted GDPR banner. Show more

GDPRify - Smart GDPR Banner is a versatile app designed to help businesses manage their GDPR compliance effortlessly. With built-in audit logs, it allows users to keep detailed records of consent activities. The app offers flexible configuration options, such as hiding the banner for users outside the EU or after their first page view, enhancing user experience and potentially increasing sales. Its geolocation feature intelligently detects EU visitors, ensuring the banner is shown only where necessary. Professionally translated into all 23 EU languages, the app caters to a diverse audience. Additionally, GDPRify simplifies cookie policy management by automatically generating and hosting an external cookie policy for your site, ensuring compliance is as seamless as possible.

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Multilingual support

Geolocation detection

Block cookies

Geo-targeted banner

Consent logging

Automatic policy generation

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B&S ‑ Add Custom Code

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Seamlessly integrate custom code for enhanced online store functionality. Show more

B&S ‑ Add Custom Code is a powerful app designed to elevate your online store by enabling the seamless embedding of custom code. With this app, you can easily integrate essential codes for site verification from Google, domain verification from Facebook, and set up Google Analytics and Facebook Pixel to enhance your store’s analytics capabilities. The app allows you to incorporate custom CSS styles into both the head and body sections of your site, enhancing your store's design and functionality. Its intuitive interface ensures that users of all skill levels can manage these tasks with ease, eliminating the need for complicated modifications. The app efficiently handles multiple codes simultaneously, allowing you to add HTML, CSS, Liquid, JQuery, and Javascript code to your store. Whether you need to modify the body or header sections, B&S ‑ Add Custom Code provides a smooth and user-friendly experience tailored to meet your customization needs.

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Custom code integration

Site verification tools

Implement analytics tags

Custom css styles

Manage multiple codes

Code in header

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Mega HTML/CSS/JS Code Embed

8.2

6 Reviews

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Easily add custom HTML, CSS, JS, and Liquid code to your store Show more

Mega HTML/CSS/JS Code Embed is a powerful app designed to enhance your online store with custom code integration, providing flexibility and creativity in managing your shop's appearance and functionality. It allows you to seamlessly add tracking pixels, create eye-catching animations, and implement sophisticated product filters without the need for complex modifications, making it suitable for users of all skill levels. With dedicated fields for HTML, CSS, JavaScript, and Liquid code, you can easily embed videos, style custom elements, and develop interactive features. The live preview feature within the Shopify theme editor lets you see your changes in real time, enabling instant refinement and adjustment. Whether you're looking to add a countdown timer, customize your checkout pages, or integrate third-party tools, the app offers a smooth experience with seamless integration and app embeds. Quick and easy to install with just one click, Mega HTML/CSS/JS Code Embed empowers you to enhance your store's functionality and aesthetics swiftly and efficiently.

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Live preview

Advanced filters

Interactive elements

Instant setup

Custom animations

Theme editor

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PageSpeed & Image Optimiser

$19.9 / Month

(3.7/5)

79 Reviews

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Improve Page Speed for better SEO rankings & Conversion Rates Show more

Flash: Page Speed Optimization is a powerful tool designed to enhance the performance of your web pages by optimizing key speed metrics such as Largest Contentful Paint (LCP), First Input Delay (FID), and First Contentful Paint (FCP). The app effectively reduces unused Javascript from your site, which not only speeds up loading times but also boosts conversion rates and lowers bounce rates. With its user-friendly 1-click install feature, Flash requires no coding expertise, making it accessible to everyone. Users can benefit from continuous support available around the clock via Slack and email. By eliminating render-blocking resources, Flash significantly improves FCP while enhancing overall SEO rankings and speed metrics. With Flash, you can effortlessly improve core web vitals and ensure a fast, smooth user experience for all visitors.

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Faster loading times

Lower bounce rate

Reduce contentful paint

Minimize input delay

Unused javascript removal

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Rocket Page Speed Optimizer

$9 / Month

(4.3/5)

96 Reviews

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Improve Google Pagespeed Score, and Fix Search Console Errors Show more

Rocket Page Speed Optimizer is a powerful app designed to enhance your store's page speed seamlessly on both desktop and mobile devices without requiring any coding skills. By focusing on optimizing critical elements like Facebook Pixel, Klaviyo, Google Analytics, and Tag Manager, the app ensures significant improvements in your store’s performance metrics. It aligns with Google's core web vitals requirements by employing lazy-loading techniques for commonly used apps and analytics. The app’s single-click optimization feature makes it easy to improve page speed and includes live chat optimization for enhanced customer interactions. With 24x7 customer assistance, users can trust in constant support and troubleshooting. Additionally, the app offers an uncomplicated uninstall option, allowing for easy removal of app code from your theme whenever necessary.

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No coding required

One-click optimization

Automatic page optimization

Google core vitals

Lazy-loading apps

Desktop & mobile

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Script Inserter

$9.99 / Month

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Easily insert Scripts, Custom Javascript and CSS in your store Show more

Script Inserter is a convenient application designed to simplify the process of embedding scripts in your online store. With this tool, there's no need to meddle with your shop's theme; simply copy and paste your code snippets into Script Inserter, and it will handle the rest, ensuring seamless integration. Whether you wish to implement the scripts on your store's web front, order status page, or both, Script Inserter gives you that flexibility. The app ensures that your scripts remain intact and functional even when you decide to switch your store's theme. It supports an unlimited number of JavaScript and CSS scripts, enabling enhanced customization. Users can also benefit from fast response times and reliable service, all while having the peace of mind that their information is kept private.

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Easily insert scripts

Supports javascript and css

Copy-paste code

Load on web front

Load on order status page

Theme change compatibility

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CodeByHooks

8.2

1 Reviews

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Easily run scalable JavaScript code with BigCommerce webhooks. No servers needed.

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Shopify Javascript deferral apps

Related Categories

Price

Based on reviews

Showing 1 to 15 of 2 Apps

Thunder Page Speed Optimizer

Hyperspeed EXTREME Page Speed

JsRates: Custom Shipping Rates

MinifyMe ‑ File Optimizer

IBuyUPay

Iconaro ‑ Snappy Custom Icons

EZ Custom HTML

CodeUp ‑ Add Custom Code

GDPRify ‑ Smart GDPR Banner

B&S ‑ Add Custom Code

Mega HTML/CSS/JS Code Embed

PageSpeed & Image Optimiser

Rocket Page Speed Optimizer

Script Inserter

CodeByHooks