Placeholder Image Generator

Placeholder images are generated programmatically using the HTML5 Canvas API. The process creates a canvas element of specified dimensions, fills it with a background color, draws centered text (typically showing the image dimensions or a custom label), and exports the result as a PNG or JPEG data URL.



Standard placeholder images (like the classic grey boxes used in web design) are created with a neutral gray background and dimension text (e.g., "400×300"). Custom variations allow choosing background color, text color, font size, the label text itself, and whether to show dimensions or custom text. The canvas API provides all the primitives needed for this simple generation.



The generated image can be downloaded directly or its URL copied for use in HTML img src attributes or CSS background-image properties. Unlike external placeholder services (placeholder.com, via.placeholder.com), this tool generates images locally without network requests, which is useful for offline development or when external services are unavailable.

1. Website Wireframing and Mockups
During wireframing and early design phases, actual content images aren't available yet. Placeholder images fill image spaces in layouts, allowing designers to evaluate composition, spacing, and proportions before final imagery is ready. Different-sized placeholders for different content types (hero, thumbnail, avatar) help establish visual hierarchy.



2. Frontend Development Before Content
Frontend developers implementing a design before content is ready use placeholder images to test layouts, check responsive breakpoints, and verify image loading behavior. Correct-dimension placeholders ensure the layout is tested with realistic image sizes rather than distorted final images.



3. Component and Template Testing
UI component libraries and templates need documentation showing each component with example imagery. Generating dimension-specific placeholders for each component size creates consistent, professional documentation without needing actual photographs for every example.



4. Email Template Development
HTML email templates with images need placeholder images during development that match the final image dimensions to verify layout. Email clients can render images differently, and testing with correct-dimension placeholders reveals layout issues before actual images are available.



5. Presentation and Proposal Mockups
Design presentations and project proposals often include screen mockups with placeholder images where final imagery hasn't been selected. Custom-colored placeholders with clear labels (PRODUCT PHOTO, TEAM HEADSHOT) communicate image intent clearly in design presentations.

• Match aspect ratios precisely: Use the exact pixel dimensions your design requires. A placeholder at the wrong aspect ratio will cause layout shifts when replaced with actual images if the container doesn't have fixed dimensions.



• Use colored placeholders for content categories: Different colors for different content types (blue for user photos, green for product images, orange for article thumbnails) makes wireframes more readable and communicates content intent clearly.



• Include dimension labels: Including the dimension in the placeholder text (400×300) helps during development to quickly verify that the correct size image will be used in each location.



• Generate retina-ready placeholders: For retina/HiDPI displays, generate placeholders at 2x or 3x the display size. A 200×200px avatar on a retina screen should use a 400×400px placeholder.