灰階轉換器
FREE使用多種專業方法將彩色圖片轉換為灰階或經典黑白。免費、即時、無品質損失。
使用多種專業方法將彩色圖片轉換為灰階或經典黑白。免費、即時、無品質損失。
The Free Grayscale Converter by Nano Banana transforms color images into stunning black and white photos or smooth grayscale images. Choose from multiple conversion algorithms—Luminosity, Average, Desaturation—for different artistic effects. Adjust intensity, contrast, and brightness for perfect results. Whether you're creating artistic portraits, preparing images for print, or achieving that classic monochrome aesthetic, our tool delivers professional quality. 100% free, browser-based, no watermarks.
Choose Luminosity (best for photos), Average (fast), or Desaturation for different grayscale results.
Beyond grayscale—create pure black and white with adjustable threshold for dramatic high-contrast images.
Adjust intensity, contrast, and brightness sliders for perfect artistic effect.
See changes instantly as you adjust. Compare before/after with one click.
Convert multiple images at once with the same settings. Perfect for photo series.
Export in full resolution. No quality loss during conversion.
Drag and drop or click to upload. Supports JPG, PNG, WebP formats up to 50MB.
Select grayscale (smooth tones) or true black & white (high contrast). Pick algorithm.
Fine-tune intensity, contrast, brightness. Preview changes in real-time.
Save your professional black and white or grayscale image. No watermarks.
Weighted conversion that preserves perceived brightness. Best for portraits and photos.
Pure B&W with adjustable threshold. Create dramatic high-contrast images.
Blend grayscale with original color. Create subtle desaturated effects.
Boost contrast for punchy monochrome. Reduce for soft, dreamy effect.
Save as JPG, PNG, or WebP. Choose quality level for optimal file size.
PNG transparency maintained in grayscale conversion. Perfect for graphics.
Convert portraits to timeless black and white. Emphasize emotion and texture.
Create dramatic monochrome art. Remove color distractions, focus on composition.
Convert color scans to grayscale for printing. Reduce file size and ink usage.
Create cohesive B&W Instagram feed. Stand out with monochrome content.
Prepare images for single-color printing. Ensure proper contrast for readability.
Grayscale images are smaller. Improve page load times with monochrome graphics.
Luminosity works best for photos. Average is faster for batch processing. Experiment to see differences.
Grayscale images often benefit from 10-20% contrast boost to maintain visual punch.
High contrast B&W suits dramatic subjects. Soft grayscale better for gentle, romantic images.
Grayscale conversion removes color permanently. Always save original color versions.
Screen grayscale may look different when printed. Do test prints for important projects.
Compare our free grayscale tool with other options.
| 功能 | Nano Banana | 其他 |
|---|---|---|
| 價格 | 永久免費 | Lightroom: $9.99/mo, Photoshop: $20.99/mo |
| Algorithms | Multiple (Luminosity, Average, Desaturation) | Usually single method |
| Fine Controls | Intensity, contrast, brightness sliders | Varies by tool |
| 處理 | 即時，基於瀏覽器 | Requires software installation |
| 批次支援 | 是的，無限制 | 通常需要付費版 |
| 學習曲線 | 無 | 專業工具需要培訓 |
Portrait Photographer
“The Luminosity algorithm produces beautiful B&W portraits. Better than my paid software.”
Instagram Creator
“Perfect for creating my monochrome feed aesthetic. So much easier than phone apps.”
Graphic Designer
“Great for preparing images for single-color print jobs. Saves me time in Photoshop.”
Grayscale uses 256 shades of gray for smooth transitions. True B&W uses only pure black and white pixels for high-contrast dramatic effect.
Upload an Image
Drag and drop or click to select