What is optimize-jpeg?

A file-optimization skill for reducing the size of JPEG images, either without changing image quality or by recompressing them.

Use it to prepare photo galleries, blog images, or folders of JPEGs for the web, including as part of a broader web-preparation process.

It reduces storage and upload size while offering a choice between preserving the original image data and accepting some quality change for smaller files.

optimize-jpeg — Skill for Claude Code by danielrosehill

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add danielrosehill/Claude-Image-Production-Plugin --skill optimize-jpeg

Clone the repo

git clone --depth 1 https://github.com/danielrosehill/Claude-Image-Production-Plugin

Made for: Claude Code.

Or install image-production, the plugin that ships this one along with the rest of its 29 skills, 19 commands.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/danielrosehill/claude-image-production-plugin/optimize-jpeg.svg)](https://agentmods.dev/skills/danielrosehill/claude-image-production-plugin/optimize-jpeg)

Your own site

<a href="https://agentmods.dev/skills/danielrosehill/claude-image-production-plugin/optimize-jpeg"><img src="https://agentmods.dev/badge/skills/danielrosehill/claude-image-production-plugin/optimize-jpeg.svg" alt="Measured on agentmods" height="20"></a>

Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 958 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00070	$0.00958
Opus 5	$0.00035	$0.00479
Sonnet 5	$0.00014	$0.00192
Haiku 4.5	$0.00007	$0.00096

Measured 7d ago against content hash 71e6a3edee67, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

optimize-jpeg scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/optimize-jpeg/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Optimize JPEG

Squeeze JPEG file size. Two modes:

lossless (default) — jpegoptim --strip-all. Repacks Huffman tables and strips metadata. No re-encode, no quality change.
recompress — mozjpeg (cjpeg-mozjpeg). Re-encodes with better quantisation tables; 10–15% smaller than libjpeg-turbo for the same SSIM. Quality flag controls trade-off.

When to use

Web-prep: photo galleries, blog images, anything destined for upload.
Archive squeeze: lossless mode is the no-regret option for any JPEG-heavy folder.
Pre-step inside web-ready orchestrator.

Do not use this skill when:

Source is PNG → use optimize-png.
Source is HEIC/RAW/TIFF — pipe through web-ready (or convert first).
The JPEG is already heavily compressed (<70% quality estimate) — recompress will visibly degrade.

Inputs

Input — file or directory. Required.
Mode — lossless (default) or recompress.
Recursive — --recursive for directory descent.
In-place — default. --output-dir <path> to write copies.
Quality (mode=recompress) — cjpeg-mozjpeg -quality N. Default 82 (web-quality). 90 for archival; 75 for aggressive web compression.
Strip metadata — default on for both modes. EXIF/IPTC/XMP gone. Use --keep-metadata to preserve.
Progressive — default on. Smaller files + better perceived load. --baseline to disable for compatibility with very old decoders.

Procedure

Verify the relevant binary. which jpegoptim for lossless; which cjpeg-mozjpeg (or fallback which cjpeg) for recompress. If missing, point at install-deps.
Enumerate inputs (JPEG/JPG only — skip with note).
Lossless (jpegoptim):
```
jpegoptim --strip-all --all-progressive [--dest <out-dir>] "<input>"
```
--all-progressive forces progressive output (smaller). --strip-all removes EXIF/IPTC/XMP/comments. Drop these if --keep-metadata was set.
Recompress (mozjpeg):

mozjpeg's CLI is decode-then-encode, so for in-place behaviour:

Read the full file on GitHub · 75 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

7d ago First seen · 75 lines · 70 tokens per session scan A 71e6a3edee67

Subscribe to this mod's changes

optimize-jpeg is a skill published in the GitHub repository danielrosehill/Claude-Image-Production-Plugin (16 stars, last pushed 20d ago), licensed MIT. It adds 70 tokens to every session and 958 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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