Jenee

Mock Image Generator

Quickly create placeholder images. Adjust background/text colors, font size, text, and corner radii (R), then save as PNG/JPG.

px
px

Width/height: 1–4000 px. Generation is limited if total pixels exceed 16M.

Common Sizes

Web/Banner

SNS

px

Corner Radius

px
px
px
px

Corner radius in pixels per corner. If too large, values are auto-adjusted to fit.

Preview

How to Use

  1. STEP 1
    Set image size, background color, text color, and format.
  2. STEP 2
    Optionally adjust text, font size, and corner radii (R).
  3. STEP 3
    The preview updates automatically when you change settings.
  4. STEP 4
    If it looks good, save with the download button.
  • Max size is 4000x4000. Images over 16 million pixels are restricted.
  • All processing is done in your browser. No images are sent to servers.
  • JPG is lossy compression and may slightly degrade details.

Tips

1

PNG is great for transparency and crisp text; JPG is useful when you want smaller file sizes with photo-like backgrounds.

2

For high-DPI displays, generate at 2x/3x (e.g., 1200×800 instead of 600×400) for sharper rendering.

3

Aim for a contrast ratio of at least 4.5:1 between text and background for readability (per WCAG).

4

Common aspect ratios: 1:1 (square), 16:9 (thumbnail/video), 4:3 (slides), 9:16 (stories).

5

Very large corner radii can collide with text. If space feels tight, reduce the font size or increase the canvas size.

6

JPG doesn’t support transparency. If you need transparent rounded corners, use PNG.

7

Text is drawn using system fonts. For pixel-perfect design fidelity, fine-tune in a design tool after download.

8

Huge images (near ~16M pixels) may stress device memory. Prefer the smallest size that meets your needs.

FAQ

  • QUESTION 1

    Is it okay to leave the text empty?

    If empty, the default text “width x height” will be displayed.

  • QUESTION 2

    Any decorations other than rounded corners?

    The initial version supports rounded corners only. With enough demand, we’ll consider borders, padding, shadows, etc.

  • QUESTION 3

    Can I set DPI (resolution)?

    For the web, pixel count matters; DPI metadata is mostly for print. This tool generates by pixels. Adjust on-page display via CSS after download.

  • QUESTION 4

    Can I make transparent PNGs?

    Yes. With PNG, the outside of rounded corners is transparent. JPG cannot be transparent and will draw a flat background.

  • QUESTION 5

    Does it support multi-line text or line breaks?

    Currently single-line only. Long text is auto-shrunk. For multi-line text, edit the downloaded image in an editor.

  • QUESTION 6

    Can I change the font family?

    System font stack is used. Web font selection isn’t supported yet. If you need exact fonts, use a design tool after download.

  • QUESTION 7

    Can I change the file name?

    It saves as “mock-WxH.ext” for now. Please rename after saving. If there’s demand, we’ll add custom file names.

  • QUESTION 8

    Why do very large sizes sometimes fail?

    Browsers have memory/rendering limits. Extremely large sizes may fail or crash. We cap total pixels at 16M for safety.

  • QUESTION 9

    Is there an API?

    No. Everything runs entirely in the browser—no server API is exposed (for abuse prevention and privacy).

  • QUESTION 10

    Do you support SVG output?

    Currently PNG/JPG only. If there’s enough demand, we’ll consider SVG or WebP.

Feedback (Contact)