Guide · Agent skill
How to use the Image CDN Review agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The Image CDN Review agent skill is a checklist-style guide that tells an AI agent how to review how a website delivers its images. It is built on the image rule "Serve images from a CDN" from the Front-End Checklist project. This guide explains what the skill does, how to install it, how to ask for a review in plain language, and what to watch for.
Image CDN Reviewthedaviddias/Front-End-Checklist · MIT Download the skill Quick start
- 1Download the ZIP. Get the image-cdn skill ZIP from this page.
- 2Unzip into a skills folder. Extract it into ~/.claude/skills/ for all projects, or into a project's .claude/skills/ folder for one project.
- 3Or upload it in the Claude apps. Go to Settings → Capabilities → Skills and upload the ZIP.
- 4Describe the review you want. Ask in plain language, naming the page, folder or component to check.
- 5Review the findings. Read the flagged files and suggested fixes the agent lists.
- 6Confirm in DevTools. Reload the page with the Network tab open and compare image sizes and domains before and after changes.
What the image-cdn skill makes the agent do
An agent skill is a folder of instructions that an AI agent loads when a task matches the skill's description. The image-cdn skill is triggered when you review image assets, markup, or CDN and build transforms related to serving images from a CDN.
When it applies, the agent checks whether images come from an image CDN, which is a service that automatically resizes, optimizes and converts pictures. Named examples in the source are Cloudinary, Imgix, Cloudflare Images and Vercel. The review looks at encoded size, rendered size, loading strategy and above-the-fold impact together.
- Checks whether images are served from a CDN or image optimization service
- Flags oversized or poorly formatted images
- Looks at format choice (for example WebP or AVIF through automatic conversion), sizing and loading behaviour
- Suggests fixes and describes how to confirm them in browser DevTools
Install the image-cdn skill
Download the skill's ZIP file from this page and unzip it. The skill contains two files: SKILL.md and references/rule.md.
To make it available to Claude Code for all your projects, unzip it into ~/.claude/skills/. To use it only in one project, unzip it into that project's .claude/skills/ folder.
To use it in the Claude apps instead, upload the ZIP under Settings → Capabilities → Skills.
- Personal install: ~/.claude/skills/
- Project install: .claude/skills/ inside your project folder
- Claude apps: Settings → Capabilities → Skills, then upload the ZIP
Trigger the skill with natural requests
You do not need to type a special command. Describe the task in ordinary language that matches the skill's purpose, such as asking the agent to review how your site's images are delivered. The agent will load the skill when the request matches its description.
Be specific about the scope. Pointing the agent at a folder, page or component gives it files to inspect, which the skill needs in order to flag exact problems.
- "Check whether the images on our product pages are served from a CDN."
- "Review the image markup in this project for size and loading problems."
- "Would an image CDN like Cloudinary or Imgix help our homepage load faster?"
What a review produces
The skill's code review guidance asks the agent to flag exact files or components where format choice, sizing or loading behaviour breaks the rule, and to describe how to confirm the fix in DevTools. Expect a list of findings tied to files, with suggested changes.
The reference file includes example markup for three providers. Cloudinary uses URL parameters such as w_400, h_300, c_fill, f_auto and q_auto. Imgix uses parameters such as w, h, fit and auto=format,compress. Cloudflare Images uses an imagedelivery.net URL with variants. These are examples from the source; check the current provider documentation before relying on any parameter.
<img src="https://res.cloudinary.com/demo/image/upload/w_400,h_300,c_fill,f_auto,q_auto/sample.jpg">Check the results yourself in browser DevTools
The skill tells the agent to describe how to verify fixes in DevTools. You can do the same check yourself: open the Network panel, reload the page, and look at the size and type of each image response. Confirm that images are delivered from the CDN host and that the format matches what you expect.
Before and after measurements are the reliable way to judge whether a change helped.
- Open DevTools, go to the Network tab and reload the page
- Filter by Img to see only image requests
- Compare transferred size and domain before and after a change
What people use it for
- Auditing a product listing page for oversized images before a page speed review
- Deciding whether a team should adopt an image CDN such as Cloudinary, Imgix or Cloudflare Images
- Giving a designer or marketer a quick view of how site images are delivered
- Reviewing a front-end project's image markup for missing responsive sizing
Frequently asked questions
How do I install the image-cdn agent skill?
Download the ZIP from this page and unzip it into ~/.claude/skills/ for personal use, or into a project's .claude/skills/ folder for one project. In the Claude apps, you can instead upload the ZIP under Settings → Capabilities → Skills.
What do I need to use this skill?
The skill lists no requirements. It does not run scripts and does not use the network. You do need files or a site to review, since the skill works on images, markup and delivery configuration.
Is the image-cdn skill free?
The skill is published under the MIT licence, as stated on this page. Check the licence file in the source repository for the full terms.
Will the skill set up a Cloudinary or Imgix account for me?
No. The skill gives guidance and a review only. It does not configure a live CDN account automatically, and its review may miss context outside the files it can see.
Are there alternatives to this skill?
Yes. You can read the Serve images from a CDN rule on frontendchecklist.io directly, or run your own check in browser DevTools. The skill is useful when you want an agent to review files against this rule for you.
Is it safe to move my images to a third-party CDN?
Check first. Moving images to a third-party CDN sends them to an outside provider, so sites with strict data-residency or privacy rules should review that before adopting one.
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Our verdict
Use the image-cdn skill if you are a front-end developer, a team deciding on an image CDN, or a designer or marketer who wants a structured check of how site images are delivered. Skip it if your project has no web images or front-end code, or if you need the agent to set up a CDN for you, since it only provides guidance.
Download the skill