svg-logo-maker（svg 徽标制作器）

SVG Logo Maker

Generate world-class minimalist SVG logos using svg.js for programmatic construction, browser-based visual verification, and automated SVG export.

Why svg.js? Writing raw SVG path data is extremely error-prone for AI. svg.js provides high-level shape methods (rect(), circle(), polygon(), group(), gradient(), mask(), transform()) that map naturally to function calls — which AI excels at. The browser renders the result, enabling visual iteration.

Five Principles of Effective Logo Design

These principles guide every decision throughout the workflow. Evaluate all designs against them.

Reference Library

This skill bundles assets/ containing logos from leading global brands in two formats:

Brands included: Apple, OpenAI, Anthropic, Claude, Claude Code, Cursor, Google, Figma, Meta, Midjourney, Grok, DeepSeek, Doubao, Moonshot, Ollama, Cloudflare, Microsoft, AWS, IBM, Gemini, Antigravity.

The reference logos are located at: {SKILL_DIR}/assets/

How to Use the Reference Library

1. Visual study (PNG): Before designing, read 3–5 PNG files relevant to the target industry/style using the Read tool. The AI can see the rendered logo, analyze its visual structure, and internalize design patterns that are impossible to learn from SVG code alone.
2. Technical study (SVG): After visual study, read the corresponding SVG files to understand how the visual result was achieved in code — path construction, use of groups, transforms, gradients, and masks.
3. Cross-reference: Always study both formats for the same logo. The PNG shows *what* to achieve; the SVG shows *how* to build it.

Workflow

Phase 1 — Brand Identity & Requirement Gathering

A logo translates an entire brand identity into a single mark. Invest heavily in this phase — a logo built on shallow understanding will look generic.

1a. Brand Identity Deep-Dive

Extract or infer the following from the user's request. For minimal input, infer reasonable defaults and state assumptions explicitly.

1b. Logo Requirements

Logo Type Guide

Choose the type that best serves the brand's needs:

Phase 2 — Visual Study of Reference Logos

MANDATORY before designing. Read PNG reference logos to build visual intuition.

1. Select 3–5 reference logos from {SKILL_DIR}/assets/ that are most relevant to the target brand's industry, style, or logo type. Use the Read tool to view the PNG files — AI can visually parse these images.
2. Read the corresponding SVG files for the selected logos to understand their construction technique.
3. Document observations — For each reference logo studied, note:

- What makes the design effective (shape language, negative space, balance) - What construction technique was used (geometric primitives, paths, masks) - What can be borrowed or adapted for the current project

This visual study directly informs the design plan. Reference specific logos when justifying design decisions.

Phase 3 — Design Plan

Before writing any code, produce a structured design plan. Present it to the user for confirmation before proceeding.

Design Plan Template

## Logo Design Plan: [Brand Name]

### 1. Design Concept
- **Core metaphor**: [What real-world object/shape/idea the logo abstracts]
- **Visual narrative**: [One sentence describing what the viewer should "read" from the logo]
- **Inspiration sources**: [Which reference logos (from Phase 2 visual study) inform this direction and why — cite specific PNG files studied]
- **Uniqueness check**: [How this design avoids clichéd symbols and stands apart from competitors]

### 2. Form Language
- **Geometry**: [Geometric primitives used — circles, rectangles, triangles, curves]
- **Shape semantics**: [Why these shapes were chosen — see Shape Psychology reference]
- **Proportions**: [Grid system, golden ratio, modular scale, or freeform]
- **Negative space**: [How white space participates in the design — any hidden forms or clever reveals]
- **Optical balance**: [Weight distribution and visual center of gravity]
- **Visual hierarchy**: [Which element draws the eye first, second, third]

### 3. Typography (if applicable)
- **Font personality**: [Display / Serif / Sans-serif / Monospace / Slab serif / Script — see Typography Guide]
- **Letterform treatment**: [Custom geometric construction, modified typeface, or hand-drawn feel]
- **Weight and spacing**: [Stroke width rationale, letter-spacing logic]
- **Readability at scale**: [How it reads at favicon size vs. billboard]

### 4. Color Strategy
- **Design approach**: Monochrome first, color second
- **Monochrome version**: [How the logo works in pure black on white]
- **Primary palette**: [Hex values with rationale — see Color Psychology reference]
- **Color scheme type**: [Complementary / Analogous / Triadic / Monochromatic — see Color Theory reference]
- **Color meaning**: [Psychological and cultural associations of chosen colors]
- **Contrast check**: [Sufficient contrast between elements for readability]

### 5. Construction Plan
- **svg.js strategy**: [Which shapes, groups, transforms, masks to use]
- **viewBox**: [Dimensions, typically 0 0 512 512]
- **Scalability target**: [Favicon to billboard]
- **Variants planned**: [Primary logo, compact/icon variant, monochrome variant]

Phase 4 — SVG Construction with svg.js

Do NOT write raw SVG markup. Use svg.js to construct the logo programmatically.

Critical Rule: Monochrome First

Always build the logo in monochrome (black on white) first. This ensures the design works through form alone, without relying on color as a crutch. Only add color after the monochrome version passes visual review.

Step 1: Create the HTML Workspace

Write a file named _logo-workspace.html in the output directory with this scaffold:

<!DOCTYPE html>
<html>
<head>
  <title>Logo Workspace</title>
  <script src="https://cdn.jsdelivr.net/npm/@svgdotjs/svg.js@3.0/dist/svg.min.js"></script>
  <style>
    body {
      margin: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 32px;
      padding: 48px 24px;
      min-height: 100vh;
      background: #e8e8e8;
      font-family: system-ui, sans-serif;
    }
    .preview {
      background: white;
      box-shadow: 0 4px 24px rgba(0,0,0,0.12);
    }
    .label {
      font-size: 13px;
      color: #666;
      margin-bottom: 8px;
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }
    .size-row {
      display: flex;
      gap: 24px;
      align-items: end;
    }
    .size-item { text-align: center; }
    textarea#svg-output {
      position: fixed;
      bottom: 0; left: 0;
      width: 1px; height: 1px;
      opacity: 0;
      pointer-events: none;
    }
  </style>
</head>
<body>
  <div>
    <div class="label">Primary — 512×512</div>
    <div id="canvas" class="preview"></div>
  </div>
  <div>
    <div class="label">Scale test</div>
    <div class="size-row">
      <div class="size-item">
        <div class="label">128px</div>
        <div id="preview-128" class="preview"></div>
      </div>
      <div class="size-item">
        <div class="label">64px</div>
        <div id="preview-64" class="preview"></div>
      </div>
      <div class="size-item">
        <div class="label">32px</div>
        <div id="preview-32" class="preview"></div>
      </div>
    </div>
  </div>
  <textarea id="svg-output"></textarea>
  <script>
    var draw = SVG().addTo('#canvas').size(512, 512).viewbox(0, 0, 512, 512);

    // ========== LOGO DRAWING CODE (MONOCHROME FIRST) ==========

    // [AI writes svg.js code here — BLACK ON WHITE ONLY in first pass]

    // ========== END LOGO CODE ==========

    // --- Scale previews ---
    var svgMarkup = draw.node.outerHTML;
    [128, 64, 32].forEach(function(s) {
      var el = document.getElementById('preview-' + s);
      el.innerHTML = svgMarkup;
      var svg = el.querySelector('svg');
      svg.setAttribute('width', s);
      svg.setAttribute('height', s);
    });

    // --- Export ---
    var svgEl = draw.node;
    svgEl.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
    var output = svgEl.outerHTML;
    output = output.replace(/\s*svgjs:data="[^"]*"/g, '');
    output = output.replace(/\s*class="[^"]*"/g, '');
    document.getElementById('svg-output').value = output;
  </script>
</body>
</html>

Key improvement over a single canvas: The workspace now shows scale previews at 128px, 64px, and 32px alongside the primary 512px canvas. This directly tests the Readability principle — if the logo is illegible at 32px, simplify before adding color.

Critical: The <textarea id="svg-output"> stores the exported SVG for extraction. Do not remove it.

Step 2: Write the Drawing Code (Monochrome)

Place svg.js code between the LOGO DRAWING CODE markers. Use only black (#000 or #1a1a1a) fills in the first pass. Prefer high-level shape methods over raw path data.

svg.js API Reference (Logo-Relevant Subset)

Shapes:

draw.rect(width, height)              // Rectangle
draw.rect(w, h).radius(r)             // Rounded rectangle
draw.circle(diameter)                  // Circle
draw.ellipse(width, height)           // Ellipse
draw.line(x1, y1, x2, y2)            // Line
draw.polygon('x1,y1 x2,y2 x3,y3')   // Polygon (auto-closed)
draw.polyline('x1,y1 x2,y2 x3,y3')  // Polyline (open)
draw.path('M0 0 L100 50 ...')         // SVG path (complex curves only)

Positioning & Sizing:

.move(x, y)          // Absolute position (top-left corner)
.center(x, y)        // Center element at position
.size(w, h)          // Resize element
.dx(offset)          // Relative horizontal shift
.dy(offset)          // Relative vertical shift

Styling:

.fill(color)                                    // '#f06', 'none', 'currentColor'
.fill({ color: '#f06', opacity: 0.8 })          // With opacity
.stroke({ width: 2, color: '#333' })            // Stroke
.stroke({ width: 2, color: '#333', linecap: 'round', linejoin: 'round' })
.opacity(0.5)                                    // Element-level opacity

Transforms:

.transform({ rotate: 45 })                          // Rotate degrees
.transform({ rotate: 45, origin: [256, 256] })      // Rotate around point
.transform({ scale: 2 })                            // Uniform scale
.transform({ translateX: 10, translateY: 20 })       // Translate
.transform({ rotate: 30 }, true)                     // Additive transform

Groups (essential for complex logos):

var g = draw.group()
g.rect(100, 100).fill('#f06')
g.circle(80).fill('#0f9').center(50, 50)
g.move(100, 100)              // Move entire group
g.transform({ rotate: 45 })   // Transform entire group

Gradients:

var grad = draw.gradient('linear', function(add) {
  add.stop(0, '#f06')
  add.stop(0.5, '#ff0')
  add.stop(1, '#0f9')
})
grad.from(0, 0).to(1, 1)  // Diagonal direction
draw.rect(100, 100).fill(grad)

var radial = draw.gradient('radial', function(add) {
  add.stop(0, '#fff')
  add.stop(1, '#000')
})
draw.circle(100).fill(radial)

Text (wordmarks/lettermarks):

draw.text('BRAND').font({
  family: 'Helvetica, Arial, sans-serif',
  size: 72,
  anchor: 'middle',
  weight: 'bold'
}).center(256, 256).fill('#333')

Masks (negative space effects):

var mask = draw.mask()
mask.rect(512, 512).fill('#fff')                    // White = fully visible
mask.circle(100).center(256, 256).fill('#000')      // Black = hidden

draw.rect(512, 512).fill('#f06').maskWith(mask)     // Circle punched out

Clipping:

var clip = draw.clip()
clip.circle(200).center(256, 256)

draw.rect(512, 512).fill('#f06').clipWith(clip)     // Only circle area visible

Construction Strategies

Geometric logos: Build from rect(), circle(), polygon(). Use groups with transforms for symmetry — draw one segment, clone and rotate:

for (var i = 0; i < 6; i++) {
  draw.rect(20, 80).center(256, 200).fill('#333')
    .transform({ rotate: i * 60, origin: [256, 256] })
}

Lettermark / Monogram logos: Construct from rect() for straight strokes, path() for curves. Alternatively, use text() with web-safe geometric fonts for prototyping, then verify in browser.

Abstract marks: Layer shapes with different fills. Use mask() for boolean-like operations (subtract, intersect). Group related shapes for unified transforms.

Negative space logos: Use mask() — white areas reveal, black areas hide. Draw the positive shape first, then cut out the negative form.

Emblem logos: Create an outer boundary shape (circle, shield, badge), then place text/symbol inside. Use clip() to contain elements within the boundary.

Symmetry patterns: Draw one unit in a group, then loop with rotational transforms:

var unit = draw.group()
unit.ellipse(40, 120).center(256, 190).fill('#f06')

for (var i = 1; i < 8; i++) {
  unit.clone().transform({ rotate: i * 45, origin: [256, 256] }).addTo(draw)
}

Phase 5 — Browser Preview & Iteration

This is the critical advantage: visual feedback loop with structured critique.

Step 1: Preview

1. Open the workspace in the browser: browser_navigate → file:///absolute/path/to/_logo-workspace.html
2. Lock the browser for interaction: browser_lock
3. Take a screenshot to capture the rendered logo: browser_take_screenshot

Step 2: Structured Critique (Monochrome Pass)

Evaluate the monochrome version against this rubric:

Step 3: Iterate (Monochrome)

If the monochrome design doesn't pass critique:

• Unlock the browser: browser_unlock
• Edit the JavaScript in _logo-workspace.html
• Re-lock and navigate to the same URL to reload
• Take another screenshot
• Repeat until the monochrome design is solid

Step 4: Add Color

Once the monochrome version is approved:

• Update the drawing code to replace black fills with the planned color palette
• Take a new screenshot
• Verify that color enhances (not replaces) the design's effectiveness
• Check that the color version still passes all critique criteria

Step 5: Final Critique (Color Pass)

Target 2–4 iteration cycles total (monochrome + color). If more are needed, reconsider the design approach.

Phase 6 — SVG Export & Variants

Once the logo looks correct in the browser:

1. Take a snapshot to find the textarea: browser_snapshot → find ref for textarea#svg-output
2. Extract the SVG string: browser_get_input_value → ref of textarea#svg-output
3. Post-process the SVG:

- Ensure xmlns="http://www.w3.org/2000/svg" is present on root <svg> - Add <title>[Brand Name]</title> as first child if not present - Remove any remaining svg.js artifacts (svgjs:data, generated id attributes, class attributes) - Ensure viewBox="0 0 512 512" and width="512" height="512" are set - For monochrome logos, consider replacing color fills with currentColor

1. Unlock the browser: browser_unlock
2. Save logo variants:

- Primary: {brand-name}-logo.svg — Full color version - Monochrome: {brand-name}-logo-mono.svg — Black-only version (replace all fills with #000 or currentColor) - Compact/icon (if applicable): {brand-name}-icon.svg — Symbol only, no text, optimized for small sizes

1. Delete the workspace — Remove _logo-workspace.html using the Delete tool.
2. Confirm — "Logos saved to {path}. Open them in a browser or SVG editor to preview."

Design Reference Guides

Shape Psychology

Shapes carry emotional weight. Choose shapes that reinforce brand personality.

Color Theory

Use established color relationships for harmonious palettes:

Color Psychology

Typography Guide (for Wordmarks, Lettermarks, Monograms)

When constructing letterforms programmatically with svg.js, prefer geometric construction (building letters from rect(), circle(), path()) over text() for the final logo — this avoids font-dependency issues in the exported SVG.

Design Principles — Learn from the Best

Study the reference logos in assets/ before generating. Read the PNG files to visually see each logo; read the SVG files to understand construction. Key patterns:

Apple — Single iconic silhouette. One path, one shape, universally recognized. The bite creates asymmetry and memorability.

OpenAI — Mathematical precision through geometric symmetry. Hexagonal knot with interlocking paths.

Anthropic — Lettermark reduced to pure geometry. Bold, structural, unmistakable at any size.

Cursor — 3D prism rendered flat. Light/shadow division creates depth illusion from a single shape.

Figma — Modular building blocks. Rounded rectangles in a grid, each a different color. Simple parts, complex whole.

Google — Letter "G" from four simple arcs. Color segmentation creates recognition from pure geometry.

FedEx — Hidden arrow in negative space between "E" and "x" — a discovery moment that reinforces the brand promise.

Nike — Abstract swoosh suggests motion and energy. No text needed. Ultimate simplicity.

Starbucks — Emblem containing a detailed illustration within a circular boundary. Shows that emblems can carry complexity inside a clean frame.

Quality Checklist

Before finalizing, verify against all five principles:

Simplicity:

• Can describe the logo in one sentence
• No unnecessary elements — every shape carries meaning
• 5 or fewer shape groups in the final design
• File size under 5KB (ideally under 2KB)

Timelessness:

• Avoids trendy gradients, textures, or effects
• Would look appropriate 10 years from now
• Design rooted in brand values, not aesthetics of the moment

Uniqueness:

• No clichéd symbols (lightbulb, globe, generic swoosh)
• Distinct from competitors in the same industry
• Contains a memorable detail or hidden meaning

Relevance:

• Form language matches brand personality (adjectives from Phase 1)
• Color choices align with industry and audience expectations
• Appropriate tone (playful vs. professional vs. luxurious)

Readability:

• Browser screenshot shows a clean, professional logo
• 32px preview is still legible and recognizable
• Text elements (if any) are crisp at all sizes
• Sufficient contrast between elements
• Optically centered with 8–12% padding within viewBox

Technical quality:

• Monochrome version works independently
• No overlapping shapes creating unintended artifacts
• Final .svg file is clean — no svg.js artifacts, no unnecessary IDs/classes
• Valid SVG parseable by any browser
• Logo variants delivered (primary, monochrome, compact/icon if applicable)

Common Pitfalls

• Skipping the brand identity deep-dive: A logo built on "make something cool" will be generic. Invest in Phase 1.
• Jumping to color: Design monochrome first. Color should enhance, never rescue, a weak form.
• Over-complexity: 5+ shape groups in a minimalist logo = too complex. Simplify.
• Tiny vanishing details: If invisible at 32×32, remove it. The scale test in the workspace catches this.
• Generic shapes: Every shape must carry brand-specific meaning. Avoid "abstract blob" designs.
• Clichéd symbols: Lightbulbs for ideas, globes for global, gears for engineering — find a fresher metaphor.
• Poor optical centering: Use screenshots to visually verify — don't trust coordinates alone.
• Inconsistent stroke weights: Maintain visual weight consistency across elements.
• Raw path data: Only use draw.path() for curves impossible to build from primitives. Prefer rect(), circle(), polygon(), group() + transforms.
• Skipping iteration: ALWAYS preview in browser. Never ship a logo without visual verification.
• Single variant delivery: Always deliver at minimum a color and monochrome version.

Style Direction by Industry

These are starting points, not rules. Break conventions when the brand demands it.