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Ubify Media & Design Operations
UI/UX & DIGITAL MEDIA SPECIALISTS
About This Tool
Placeholder Image Generator creates custom blank graphic mockups for web design, software wireframes, and responsive layout prototyping. When building user interfaces or testing image grids, you often need placeholder visuals with exact pixel dimensions before final artwork is ready.
### Geometry and Typography Settings The generator renders directly to an HTML5 canvas element using your custom parameters: - **Pixel Dimensions:** Define exact width (w) and height (h) in pixels to match your intended banner, thumbnail, or card slot. - **Palette Controls:** Select any background fill color (bg) and contrasting label color (fg) using standard hex values. - **Proportional Text Sizing:** Font size scales automatically as Math.min(w, h) / 10 using bold Inter typography, centered horizontally and vertically at (w / 2, h / 2). - **Custom or Automatic Text:** Enter a custom descriptor (such as "Hero Card" or "Avatar 1×1"), or leave the field blank to display the dimension label (such as "800 × 450").
### Worked Example: Social Share Open Graph Placeholder Suppose a frontend developer needs an Open Graph preview placeholder for a blog template: 1. **Set Dimensions:** Width = 1200 px, Height = 630 px (standard 1.91:1 social card ratio). 2. **Assign Colors:** Background = #1e293b (slate blue), Text = #38bdf8 (sky blue). 3. **Enter Custom Label:** Type "Blog Article Header Mockup". 4. **Calculations:** - Canvas size: 1200 × 630 pixels. - Text font size: Math.min(1200, 630) / 10 = 630 / 10 = 63 px bold Inter. - Center alignment: Text baseline set to middle, text align set to center at coordinate (600, 315). 5. **Download Export:** Click Download Image to save placeholder-1200x630.png (a crisp 14 KB PNG file) in under 15 ms.
### In-Browser Generation Details The placeholder image is generated entirely inside your browser using the HTML5 Canvas 2D API. The canvas data is converted to a PNG data URL and downloaded straight to your disk. Zero external network requests are made, and no images are uploaded.
How to Use
- 1
Enter the target Width and Height in pixels for your placeholder mockup.
- 2
Choose a background fill color and a contrasting text color using the hex input fields.
- 3
Optionally enter custom label text, or leave blank to display the pixel dimensions.
- 4
Check the real-time canvas preview in the center display panel.
- 5
Click Download Image to save your placeholder PNG file as placeholder-[width]x[height].png.
Frequently Asked Questions
What format does the placeholder image export as?
The tool exports a standard PNG file named placeholder-[width]x[height].png using the canvas toDataURL method.
Can I use custom text instead of dimension numbers?
Yes. Entering any text string into the Label field overrides the default dimension text and centers your custom text on the canvas.
How is the label font size determined?
The font size is calculated dynamically as one-tenth of the smaller dimension (Math.min(width, height) / 10) to prevent text overflow.
Does generating placeholder images require an internet connection?
Once the page is loaded, all canvas rendering and PNG creation execute locally in your web browser with zero network calls.