Cover Image Generator

📖 Tool Introduction

The Cover Image Generator is a fast, focused tool for producing article headers, video thumbnails, event banners and social share cards. A surprising number of content creators get stuck at the very last step of publishing: putting together a decent-looking cover. Opening a full design suite is overkill, and reusing the same template makes every post look identical to the next. This tool collapses the whole routine into three steps: type a main title and a subtitle, choose an aspect ratio, then pick a pair of gradient colours. Your browser draws a high-resolution banner directly on a local Canvas and hands it back as a downloadable PNG. Five ratios are built in: the cinematic 2.35:1, the standard 16:9 video frame, the classic 4:3 presentation slide, the square 1:1 social tile, and the ultra-wide 21:9 cinema strip, which together cover the vast majority of publishing destinations. To keep the text legible on any gradient, the tool measures the average brightness of the two chosen colours and switches the lettering between white and near-black automatically, so a light-pink background never leaves you with invisible pink text. When the main title is unusually long, the font size shrinks proportionally to the banner width instead of overflowing the frame, which means you always get a balanced composition even if you forget to trim your headline. Because rendering happens on a local canvas, no image is ever uploaded, so sensitive branding or unreleased campaign art can be prepared without any privacy concern. The whole experience is tuned so that going from a blank idea to a finished PNG takes roughly fifteen seconds, which is exactly what a busy creator needs between drafting and publishing. No account is required, and the page works fully offline as well, so you can prepare campaign banners even on a restricted connection.

✨ Key Features

• Five aspect ratios: 2.35:1, 16:9, 4:3, 1:1 and 21:9, switched with one click
• Diagonal gradient background: freely choose start and end colours to match any brand
• Centred title and subtitle: vertical spacing is balanced automatically
• Smart text colouring: white or dark lettering chosen by background brightness
• Adaptive font size: long titles scale down rather than spilling outside the frame
• Live preview and high-resolution export: every tweak shows instantly, saved as a crisp PNG

📝 How to Use

1. Type the large headline you want to show into the main title field
2. Type a supporting line into the subtitle field, or leave it blank
3. Pick the aspect ratio that matches your publishing channel
4. Use the colour pickers to choose the gradient start and end colours
5. Click Generate Cover, then click Download PNG when you are happy with it

⚠️ Notes

• Title required: generating without a title shows a prompt instead of an empty image
• Adaptive size: very long titles shrink to a minimum readable size; keep headlines under about fifteen characters
• Contrast safety: automatic colouring covers common gradients, and pale backgrounds switch to dark text
• Fully offline: all drawing runs on a local Canvas; images are never uploaded
• Export sizes: each ratio uses a fixed base resolution, so crop per channel when needed