为什么要把 PDF 转为 PNG？
PDF 适合做文档，但当图片用就不方便了。把页面转为 PNG，您得到无损图片：可插入演示文稿、用 Photoshop 编辑、发布到网上，或无需 PDF 阅读器存档。与转 JPG 不同，PNG 让文字保持锐利，还保留透明背景——非常适合幻灯片、图表和打算编辑的扫描文档。
如何将 PDF 转为 PNG
1. 把 PDF 拖到上方框内，或点击选择。
2. 选择清晰度（2 倍在所有屏幕上都很锐利；打印用 3 倍）。
3. 点击转为 PNG。每一页都在浏览器中渲染并下载——单页直接下载，多页 PDF 打包为 ZIP。
Rendering happens locally with PDF.js. Large PDFs with hundreds of pages may take a while and use significant memory.
PDF 页面用 PNG 还是 JPG？
文字、线条图或扁平图形的页面选 PNG——像素级精确。 Choose PDF 转 JPG 照片型页面选它，体积小比极致锐利更重要。
常见问题
Is PDF to PNG conversion lossless?
Yes. Each page is rasterized directly to PNG with no intermediate JPG step, so text and graphics stay exact at the chosen scale.
What scale should I choose?
2x looks sharp on retina displays and is the best default. Use 3x for print work, 1.5x for smaller files.
Are my PDFs uploaded anywhere?
No. PDF.js renders pages inside your browser. Your documents never leave your device.
Can I convert password-protected PDFs?
Only if you know the password — this tool does not crack encryption. Remove the password first, then convert.
Why is the ZIP so large?
PNG is lossless, so complex pages produce big files. For smaller output, try PDF 转 JPG instead.