visual-regression-tester

visual-regression-tester is a skill for Claude Code, Codex from lfyxhappy/lfcode. It costs 57 tokens per session (371 once invoked), scanned A, original, MIT.

A guide for finding visual changes in web, desktop, or mobile interfaces by comparing controlled screenshots or other rendered states with approved baselines. It checks whether a difference is an intended design change, a defect, or a testing-environment problem.

In plain words
What is it for?
Creating and reviewing screenshot comparisons, investigating visual regressions, and deciding when a visual test baseline should be updated.
Why use it?
It catches layout and rendering problems that source-code inspection or ordinary assertions may miss. Controlling the device, browser, data, fonts, and loading state makes comparisons more trustworthy.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Creating and reviewing screenshot comparisons, investigating visual regressions, and deciding when a…

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Install with agentmods
npx agentmods add skills/lfyxhappy/lfcode/visual-regression-tester
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 lfyxhappy/lfcode --skill visual-regression-tester
Clone the repo
git clone --depth 1 https://github.com/lfyxhappy/lfcode

Made for: Claude Code, Codex.

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.

agentmods badge for visual-regression-tester

README.md
[![agentmods](https://agentmods.dev/badge/skills/lfyxhappy/lfcode/visual-regression-tester.svg)](https://agentmods.dev/skills/lfyxhappy/lfcode/visual-regression-tester)
Your own site
<a href="https://agentmods.dev/skills/lfyxhappy/lfcode/visual-regression-tester"><img src="https://agentmods.dev/badge/skills/lfyxhappy/lfcode/visual-regression-tester.svg" alt="Measured on agentmods" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 371 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00057 $0.00371
Opus 5 $0.00028 $0.00186
Sonnet 5 $0.00011 $0.00074
Haiku 4.5 $0.00006 $0.00037

Measured yesterday against content hash c569a02f9dfe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

visual-regression-tester 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 yesterday.

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.

packages/lfcode/src/skill/lfcode/.bundle/visual-regression-tester/SKILL.md · 29 lines

What it actually says

Visual Regression Tester

Compare rendered output with deliberate baselines rather than relying on source inspection.

Workflow

  1. Read repository instructions, design requirements, existing screenshot tests, baseline ownership rules, and the actual rendered artifact to inspect.
  2. Define comparable states: viewport or device, scale factor, color scheme, locale, fonts, browser or runtime version, data fixture, navigation state, and loading readiness.
  3. Capture a baseline only from a verified intended state. Use stable test data and wait for meaningful content and fonts rather than fixed delays.
  4. Capture the candidate through the same path, then inspect the visual diff and relevant DOM, console, network, or accessibility evidence when pixels alone are ambiguous.
  5. Classify differences as intended product change, layout or styling defect, missing asset, rendering-environment variance, or unstable test setup.
  6. Update a baseline only after confirming the rendering change is intentional and reviewing the full affected surface, then rerun the focused visual check.

Boundaries

  • Keep visual assessment read-only unless the user asks to change tests, baselines, or product code.
  • Do not approve or regenerate baselines merely to make a visual test pass.
  • Do not compare screenshots with uncontrolled fonts, network data, animations, time, locale, or viewport conditions.
  • Do not expose customer content, access tokens, or sensitive screenshots in reports or committed artifacts.

Completion Check

Report the compared artifact, controlled rendering conditions, baseline decision, inspected differences, verification command, and any remaining platform variance.

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.

  1. yesterday First seen · 29 lines · 57 tokens per session scan A c569a02f9dfe

Subscribe to this mod's changes

visual-regression-tester is a skill published in the GitHub repository lfyxhappy/lfcode (2 stars, last pushed 4d ago), licensed MIT. It adds 57 tokens to every session and 371 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 2026-09-05.