image-file-size SKILL.md skillA

image-file-size from thedaviddias/front-end-checklist is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add thedaviddias/front-end-checklist/image-file-size@git:20261004.4b0ddb9

Pins git:20261004.4b0ddb9 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
thedaviddias/front-end-checklist
Path
skills/image-file-size/SKILL.md
Versions recorded
2
Latest version
git:20261004.4b0ddb9, committed Oct 4, 2026
First version recorded
May 29, 2026
Size
3,169 bytes
Repository stars
74,516
License
MIT

Use when auditing the image pipeline, static assets in `public/`, CMS-managed media, or image CDN transforms. Separate file-size problems from dimension mismatches so you can tell whether the issue is compression, format choice, or responsive delivery.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# Keep image file sizes within recommended limits

Images account for over 50% of average page weight according to HTTP Archive data. Oversized images waste user bandwidth (costly on mobile data plans), delay Largest Contentful Paint (LCP), and increase bounce rates. A 1-second delay in mobile page load can reduce conversions by up to 20% according to Google research.

## Quick Reference

- Photos: target under 200KB (WebP 80% quality); under 400KB for full-bleed hero images
- Graphics/icons: target under 50KB; use SVG for vector graphics
- WebP is typically 25-35% smaller than equivalent-quality JPEG (per web.dev)
- AVIF is typically 40-50% smaller than equivalent-quality JPEG (per web.dev)

## Check

Audit all image assets in this project. For each image: 1) Check the file size in bytes. 2) Flag any photo (JPEG/WebP/AVIF) over 200KB. 3) Flag any graphic/icon (PNG/SVG) over 100KB. 4) Flag any hero or full-width image over 400KB. 5) Flag any thumbnail (under 200px wide) over 30KB. Also check if Lighthouse reports 'Properly size images' or 'Efficiently encode images' as opportunities. Report each oversized image with its path, current size, and an estimated target size.

## Fix
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add thedaviddias/front-end-checklist/image-file-size@sha256:f6abba476b01faf4

The line at the top of this page pins the label git:20261004.4b0ddb9, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_smfeuaej43wnj7oc.svg)](https://markdownregistry.com/a/art_smfeuaej43wnj7oc)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 2 versions of this file, between May 29, 2026 and Oct 4, 2026, about one every 128 days.

versioncommittedcommitsizeaudit
git:20261004.4b0ddb9 latest2026-10-04 4b0ddb9 3,169 BA view · diff
git:20260529.7c059042026-05-29 7c05904 3,175 BA view

Audit of the latest version

A  17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (3169 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

thedaviddias/front-end-checklist · 74,516 stars · license MIT · pushed 2026-10-06 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_smfeuaej43wnj7oc
GET https://markdownregistry.com/api/v1/resolve?ref=thedaviddias/front-end-checklist/image-file-size
GET https://markdownregistry.com/api/v1/blob/f6abba476b01faf4eb995ae94da45339a51cffa77799b3c2fc91fbed72126295

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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Every file in thedaviddias/front-end-checklist

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