將 PDF 轉換為灰階
移除每一頁的色彩。
運作方式
上傳您的 PDF 並下載結果——每一頁都會轉換成灰階，移除所有色彩。
為什麼要將 PDF 轉換成灰階？
縮小檔案大小並降低黑白列印成本——彩色照片與標示在封存或內部審閱時通常不需要。
這會像壓縮一樣縮小檔案大小嗎？
通常會，這是附帶效果——但如果主要目標是達到特定檔案大小，請使用「壓縮 PDF」；此工具的任務是去除色彩，而非最佳化大小。
Can I convert back to color afterward?
No — grayscale conversion removes the color data permanently in the output file. Keep your original if you might need the color version again.
Does grayscale conversion affect scanned handwriting or signatures?
They'll render in shades of gray rather than color, but stay just as legible — grayscale only removes hue, not detail or contrast.
Is grayscale the same as black and white?
Not quite — grayscale keeps shades of gray for a smooth photographic look; true black-and-white (1-bit) has no gray at all. This tool produces grayscale, not 1-bit black-and-white.
Will I still be able to select or copy the text after converting?
No. Every page is rendered as an image and rebuilt as a flat JPEG — that's true whether the page was typed text or a scan. The result looks and prints fine, but the text is pixels, not characters, afterward, so it can't be selected, copied, or searched. If you need the text layer to survive, keep your original file and only hand out the grayscale copy for viewing or printing.