Pptx

PPTX creation, editing, and analysis

Overview

A .pptx file is a ZIP archive containing XML files and resources. Create, edit, or analyze PowerPoint presentations using text extraction, raw XML access, or html2pptx workflows. Apply this skill for programmatic presentation creation and modification.

Visual Enhancement with Scientific Schematics

When creating documents with this skill, always consider adding scientific diagrams and schematics to enhance visual communication.

If your document does not already contain schematics or diagrams:

• Use the scientific-schematics skill to generate AI-powered publication-quality diagrams
• Simply describe your desired diagram in natural language
• Nano Banana Pro will automatically generate, review, and refine the schematic

For new documents: Scientific schematics should be generated by default to visually represent key concepts, workflows, architectures, or relationships described in the text.

How to generate schematics:

python scripts/generate_schematic.py "your diagram description" -o figures/output.png

The AI will automatically:

• Create publication-quality images with proper formatting
• Review and refine through multiple iterations
• Ensure accessibility (colorblind-friendly, high contrast)
• Save outputs in the figures/ directory

When to add schematics:

• Presentation workflow diagrams for slides
• Slide design process flowcharts
• Content organization diagrams
• System architecture illustrations
• Process flow visualizations
• Any complex concept that benefits from visualization

For detailed guidance on creating schematics, refer to the scientific-schematics skill documentation.

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Reading and analyzing content

Text extraction

To read the text contents of a presentation, convert the document to markdown:

# Convert document to markdown
python -m markitdown path-to-file.pptx

Raw XML access

Raw XML access is required for: comments, speaker notes, slide layouts, animations, design elements, and complex formatting. For any of these features, unpack a presentation and read its raw XML contents.

Unpacking a file

python ooxml/scripts/unpack.py

Note: The unpack.py script is located at skills/pptx/ooxml/scripts/unpack.py relative to the project root. If the script doesn't exist at this path, use find . -name "unpack.py" to locate it.

Key file structures

• ppt/presentation.xml - Main presentation metadata and slide references
• ppt/slides/slide{N}.xml - Individual slide contents (slide1.xml, slide2.xml, etc.)
• ppt/notesSlides/notesSlide{N}.xml - Speaker notes for each slide
• ppt/comments/modernComment_*.xml - Comments for specific slides
• ppt/slideLayouts/ - Layout templates for slides
• ppt/slideMasters/ - Master slide templates
• ppt/theme/ - Theme and styling information
• ppt/media/ - Images and other media files

Typography and color extraction

When given an example design to emulate: Always analyze the presentation's typography and colors first using the methods below:

1. Read theme file: Check ppt/theme/theme1.xml for colors (`) and fonts (`)
2. Sample slide content: Examine ppt/slides/slide1.xml for actual font usage (``) and colors
3. Search for patterns: Use grep to find color (`, `) and font references across all XML files

Creating a new PowerPoint presentation without a template

When creating a new PowerPoint presentation from scratch, use the html2pptx workflow to convert HTML slides to PowerPoint with accurate positioning.

Design Principles

CRITICAL: Before creating any presentation, analyze the content and choose appropriate design elements:

1. Consider the subject matter: What is this presentation about? What tone, industry, or mood does it suggest?
2. Check for branding: If the user mentions a company/organization, consider their brand colors and identity
3. Match palette to content: Select colors that reflect the subject
4. State your approach: Explain your design choices before writing code

Requirements:

• ✅ State your content-informed design approach BEFORE writing code
• ✅ Use web-safe fonts only: Arial, Helvetica, Times New Roman, Georgia, Courier New, Verdana, Tahoma, Trebuchet MS, Impact
• ✅ Create clear visual hierarchy through size, weight, and color
• ✅ Ensure readability: strong contrast, appropriately sized text, clean alignment
• ✅ Be consistent: repeat patterns, spacing, and visual language across slides

Color Palette Selection

Choosing colors creatively:

• Think beyond defaults: What colors genuinely match this specific topic? Avoid autopilot choices.
• Consider multiple angles: Topic, industry, mood, energy level, target audience, brand identity (if mentioned)
• Be adventurous: Try unexpected combinations - a healthcare presentation doesn't have to be green, finance doesn't have to be navy
• Build your palette: Pick 3-5 colors that work together (dominant colors + supporting tones + accent)
• Ensure contrast: Text must be clearly readable on backgrounds

Example color palettes (use these to spark creativity - choose one, adapt it, or create your own):

1. Classic Blue: Deep navy (#1C2833), slate gray (#2E4053), silver (#AAB7B8), off-white (#F4F6F6)
2. Teal & Coral: Teal (#5EA8A7), deep teal (#277884), coral (#FE4447), white (#FFFFFF)
3. Bold Red: Red (#C0392B), bright red (#E74C3C), orange (#F39C12), yellow (#F1C40F), green (#2ECC71)
4. Warm Blush: Mauve (#A49393), blush (#EED6D3), rose (#E8B4B8), cream (#FAF7F2)
5. Burgundy Luxury: Burgundy (#5D1D2E), crimson (#951233), rust (#C15937), gold (#997929)
6. Deep Purple & Emerald: Purple (#B165FB), dark blue (#181B24), emerald (#40695B), white (#FFFFFF)
7. Cream & Forest Green: Cream (#FFE1C7), forest green (#40695B), white (#FCFCFC)
8. Pink & Purple: Pink (#F8275B), coral (#FF574A), rose (#FF737D), purple (#3D2F68)
9. Lime & Plum: Lime (#C5DE82), plum (#7C3A5F), coral (#FD8C6E), blue-gray (#98ACB5)
10. Black & Gold: Gold (#BF9A4A), black (#000000), cream (#F4F6F6)
11. Sage & Terracotta: Sage (#87A96B), terracotta (#E07A5F), cream (#F4F1DE), charcoal (#2C2C2C)
12. Charcoal & Red: Charcoal (#292929), red (#E33737), light gray (#CCCBCB)
13. Vibrant Orange: Orange (#F96D00), light gray (#F2F2F2), charcoal (#222831)
14. Forest Green: Black (#191A19), green (#4E9F3D), dark green (#1E5128), white (#FFFFFF)
15. Retro Rainbow: Purple (#722880), pink (#D72D51), orange (#EB5C18), amber (#F08800), gold (#DEB600)
16. Vintage Earthy: Mustard (#E3B448), sage (#CBD18F), forest green (#3A6B35), cream (#F4F1DE)
17. Coastal Rose: Old rose (#AD7670), beaver (#B49886), eggshell (#F3ECDC), ash gray (#BFD5BE)
18. Orange & Turquoise: Light orange (#FC993E), grayish turquoise (#667C6F), white (#FCFCFC)

Visual Details Options

Geometric Patterns:

• Diagonal section dividers instead of horizontal
• Asymmetric column widths (30/70, 40/60, 25/75)
• Rotated text headers at 90° or 270°
• Circular/hexagonal frames for images
• Triangular accent shapes in corners
• Overlapping shapes for depth

Border & Frame Treatments:

• Thick single-color borders (10-20pt) on one side only
• Double-line borders with contrasting colors
• Corner brackets instead of full frames
• L-shaped borders (top+left or bottom+right)
• Underline accents beneath headers (3-5pt thick)

Typography Treatments:

• Extreme size contrast (72pt headlines vs 11pt body)
• All-caps headers with wide letter spacing
• Numbered sections in oversized display type
• Monospace (Courier New) for data/stats/technical content
• Condensed fonts (Arial Narrow) for dense information
• Outlined text for emphasis

Chart & Data Styling:

• Monochrome charts with single accent color for key data
• Horizontal bar charts instead of vertical
• Dot plots instead of bar charts
• Minimal gridlines or none at all
• Data labels directly on elements (no legends)
• Oversized numbers for key metrics

Layout Innovations:

• Full-bleed images with text overlays
• Sidebar column (20-30% width) for navigation/context
• Modular grid systems (3×3, 4×4 blocks)
• Z-pattern or F-pattern content flow
• Floating text boxes over colored shapes
• Magazine-style multi-column layouts

Background Treatments:

• Solid color blocks occupying 40-60% of slide
• Gradient fills (vertical or diagonal only)
• Split backgrounds (two colors, diagonal or vertical)
• Edge-to-edge color bands
• Negative space as a design element

Layout Tips

For slides with charts or tables:

• Two-column layout (PREFERRED): Use a header spanning the full width, then two columns below - text/bullets in one column and the featured content in the other. This provides better balance and makes charts/tables more readable. Use flexbox with unequal column widths (e.g., 40%/60% split) to optimize space for each content type.
• Full-slide layout: Let the featured content (chart/table) take up the entire slide for maximum impact and readability
• NEVER vertically stack: Do not place charts/tables below text in a single column - this causes poor readability and layout issues

Workflow

1. MANDATORY - READ ENTIRE FILE: Read [html2pptx.md](html2pptx.md) completely from start to finish. NEVER set any range limits when reading this file. Read the full file content for detailed syntax, critical formatting rules, and best practices before proceeding with presentation creation.
2. Create an HTML file for each slide with proper dimensions (e.g., 720pt × 405pt for 16:9)

• Use `, -, , ` for all text content
• Use class="placeholder" for areas where charts/tables will be added (render with gray background for visibility)
• CRITICAL: Rasterize gradients and icons as PNG images FIRST using Sharp, then reference in HTML
• LAYOUT: For slides with charts/tables/images, use either full-slide layout or two-column layout for better readability

1. Create and run a JavaScript file using the [html2pptx.js](scripts/html2pptx.js) library to convert HTML slides to PowerPoint and save the presentation

• Use the html2pptx() function to process each HTML file
• Add charts and tables to placeholder areas using PptxGenJS API
• Save the presentation using pptx.writeFile()

1. Visual validation: Generate thumbnails and inspect for layout issues

• Create thumbnail grid: python scripts/thumbnail.py output.pptx workspace/thumbnails --cols 4
• Read and carefully examine the thumbnail image for:
• Text cutoff: Text being cut off by header bars, shapes, or slide edges
• Text overlap: Text overlapping with other text or shapes
• Positioning issues: Content too close to slide boundaries or other elements
• Contrast issues: Insufficient contrast between text and backgrounds
• If issues found, adjust HTML margins/spacing/colors and regenerate the presentation
• Repeat until all slides are visually correct

Editing an existing PowerPoint presentation

To edit slides in an existing PowerPoint presentation, work with the raw Office Open XML (OOXML) format. This involves unpacking the .pptx file, editing the XML content, and repacking it.

Workflow

1. MANDATORY - READ ENTIRE FILE: Read [ooxml.md](ooxml.md) (~500 lines) completely from start to finish. NEVER set any range limits when reading this file. Read the full file content for detailed guidance on OOXML structure and editing workflows before any presentation editing.
2. Unpack the presentation: python ooxml/scripts/unpack.py
3. Edit the XML files (primarily ppt/slides/slide{N}.xml and related files)
4. CRITICAL: Validate immediately after each edit and fix any validation errors before proceeding: python ooxml/scripts/validate.py --original
5. Pack the final presentation: python ooxml/scripts/pack.py

Creating a new PowerPoint presentation using a template

To create a presentation that follows an existing template's design, duplicate and re-arrange template slides before replacing placeholder context.

Workflow

1. Extract template text AND create visual thumbnail grid:

• Extract text: python -m markitdown template.pptx > template-content.md
• Read template-content.md: Read the entire file to understand the contents of the template presentation. NEVER set any range limits when reading this file.
• Create thumbnail grids: python scripts/thumbnail.py template.pptx
• See [Creating Thumbnail Grids](#creating-thumbnail-grids) section for more details

1. Analyze template and save inventory to a file:

• Visual Analysis: Review thumbnail grid(s) to understand slide layouts, design patterns, and visual structure
• Create and save a template inventory file at template-inventory.md containing:

```markdown # Template Inventory Analysis Total Slides: [count] IMPORTANT: Slides are 0-indexed (first slide = 0, last slide = count-1)

## [Category Name]

• Slide 0: [Layout code if available] - Description/purpose
• Slide 1: [Layout code] - Description/purpose
• Slide 2: [Layout code] - Description/purpose

[... EVERY slide must be listed individually with its index ...] ```

• Using the thumbnail grid: Reference the visual thumbnails to identify:
• Layout patterns (title slides, content layouts, section dividers)
• Image placeholder locations and counts
• Design consistency across slide groups
• Visual hierarchy and structure
• This inventory file is REQUIRED for selecting appropriate templates in the next step

1. Create presentation outline based on template inventory:

• Review available templates from step 2.
• Choose an intro or title template for the first slide. This should be one of the first templates.
• Choose safe, text-based layouts for the other slides.
• CRITICAL: Match layout structure to actual content:
• Single-column layouts: Use for unified narrative or single topic
• Two-column layouts: Use ONLY when there are exactly 2 distinct items/concepts
• Three-column layouts: Use ONLY when there are exactly 3 distinct items/concepts
• Image + text layouts: Use ONLY when actual images are available to insert
• Quote layouts: Use ONLY for actual quotes from people (with attribution), never for emphasis
• Never use layouts with more placeholders than available content
• If there are 2 items, don't force them into a 3-column layout
• If there are 4+ items, consider breaking into multiple slides or using a list format
• Count actual content pieces BEFORE selecting the layout
• Verify each placeholder in the chosen layout will be filled with meaningful content
• Select one option representing the best layout for each content section.
• Save outline.md with content AND template mapping that leverages available designs
• Example template mapping:

`` # Template slides to use (0-based indexing) # WARNING: Verify indices are within range! Template with 73 slides has indices 0-72 # Mapping: slide numbers from outline -> template slide indices template_mapping = [ 0, # Use slide 0 (Title/Cover) 34, # Use slide 34 (B1: Title and body) 34, # Use slide 34 again (duplicate for second B1) 50, # Use slide 50 (E1: Quote) 54, # Use slide 54 (F2: Closing + Text) ] ``

1. Duplicate, reorder, and delete slides using rearrange.py:

• Use the scripts/rearrange.py script to create a new presentation with slides in the desired order:

``bash python scripts/rearrange.py template.pptx working.pptx 0,34,34,50,52 ``

• The script handles duplicating repeated slides, deleting unused slides, and reordering automatically
• Slide ind

…

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: tristan-mcinnis
• Source: tristan-mcinnis/pptx-from-layouts-skill
• License: MIT

Install and usage instructions live in the source repository linked above.