🖼️ PDF 转 PNGPDF to PNG Converter

使用说明与常见问题How-to & FAQ

「PDF 转 PNG」是什么？What is the PDF to PNG Converter tool?

把 PDF 页面转换为无损 PNG 图片，文字和线条边缘清晰锐利，可选透明背景（适合制作贴图、幻灯片素材），支持 72–600 DPI 和页码范围，批量打包 ZIP，文件不上传。Convert PDF pages into lossless PNG images with crisp text and line edges, optionally with a transparent background for overlays and slides. 72–600 DPI, page ranges and ZIP download; files never leave your device.

如何使用「PDF 转 PNG」？How do I use the PDF to PNG Converter tool?

在「PDF 转 PNG」中，按需设置「分辨率」、「页码（留空为全部）」等选项，然后点击「转换为 PNG」、「全部下载（ZIP）」按钮即可。支持拖放文件。加密的 PDF 选好后会先出现「打开密码」栏和「打开」按钮，输入密码点「打开」后再继续。In the PDF to PNG Converter: Set "Resolution", "Pages (empty = all)", then click "Convert to PNG", "Download all (ZIP)". Drag-and-drop files is supported. For an encrypted PDF, a Password field and an Open button appear after you choose it — enter the password and click Open first.

分辨率（DPI）怎么选？Which resolution (DPI) should I pick?

72–96 DPI 适合在屏幕上查看或网页使用，150 DPI 是清晰度和体积的平衡点，200–300 DPI 适合打印或需要放大细节，600 DPI 文件会非常大。A4 页面在 150 DPI 下约为 1240×1754 像素。72–96 DPI suits screens and the web, 150 DPI balances clarity and size, 200–300 DPI is for printing or zooming in, and 600 DPI files are very large. An A4 page at 150 DPI is about 1240×1754 pixels.

透明背景是怎么实现的？How does the transparent background work?

勾选后页面不再填充白色底色，没有内容的区域保存为透明像素。注意：如果 PDF 本身画了白色背景（很多扫描件和导出的文档都会），这些区域仍然是白色。When ticked, no white base is painted, so areas without content are saved as transparent pixels. If the PDF itself paints a white background (many scans and exported documents do), those areas stay white.

中文和特殊字体能正确显示吗？Are Chinese and special fonts rendered correctly?

页面由 pdf.js 渲染，支持嵌入字体、中日韩文字（含 CMap）、透明度和 JPEG2000/JBIG2 图片；未嵌入字体的文件会用相近的标准字体替代，个别排版可能与原软件略有差异。Pages are rendered with pdf.js, which supports embedded fonts, CJK text (with CMaps), transparency and JPEG2000/JBIG2 images. Non-embedded fonts are substituted with similar standard fonts, so rare layouts may differ slightly.

加密的 PDF 可以处理吗？Can it handle password-protected PDFs?

可以。如果 PDF 需要打开密码，会提示你输入；只有权限限制（无打开密码）的文件会自动打开。输出文件不再带密码，如需加密请使用“PDF 加密”工具。Yes. If the PDF needs an open password you'll be asked for it; files with only permission restrictions open automatically. The output is not password-protected — use the Protect PDF tool if needed.

文件会上传到服务器吗？Are my files uploaded?

不会。PDF 在你的浏览器里用 pdf-lib / pdf.js 处理，文件不会离开你的设备，关闭页面后不留存任何数据。No. The PDF is processed in your browser with pdf-lib / pdf.js; files never leave your device and nothing is kept after you close the page.

「PDF 转 PNG」免费吗？需要注册吗？Is the PDF to PNG Converter free? Do I need an account?

「PDF 转 PNG」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The PDF to PNG Converter is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.