离线 · 无上传 · 浏览器本地完成Offline · no uploads · runs in the browser
PNG 转 PDF——像素不重画，页面就是这张图PNG to PDF without redrawing a pixel — page is the image
这条链路与别的路不太一样：它是「把这张 PNG 放进 PDF 容器」，不是「重画一遍再塞进去」。像素一个都不丢，产物是无损的。但无损不等于不变大——PDF 用自己的流格式重存这些像素，实测几张截图的产物落在原 PNG 的 1.1–1.3 倍，画面越碎越接近 1.5 倍。要压体积请在图片侧解决（换 WebP、缩最长边），别指望这一转。页面尺寸直接由图像像素按 96 dpi 换算成点（px × 72 ÷ 96），宽大于高就自动横向，于是它不是 A4：一张 2560×1440 的截图进去，出来的 PDF 就是一页 2560×1440 大小的纸。打印时需要选「适合页面」。This route is unlike the others: it places the PNG inside a PDF container instead of redrawing it there, so not one pixel is lost and the artifact is lossless. Lossless is not the same as the same size, though — a PDF re-stores those samples in its own stream format, and measured over several screenshots the artifact lands 1.1x–1.3x the source PNG, nearer 1.5x when the picture is finely detailed. Do the shrinking on the image side (WebP, a shorter edge) rather than hoping this hop does it. The page is computed from the image pixels at 96 dpi (px × 72 ÷ 96 points), landscape when it is wider than tall, which means it is not A4: a 2560×1440 screenshot in yields one page the size of that screenshot. Choose “fit to page” when printing.
这条链路怎么走How the route runs
PNGPNG PDFPDF
共 1 步，由扩展的路径搜索自动选出，中间产物不落盘。1 step, chosen by the extension's own path search; intermediate results never touch the disk.
会保留什么What carries over
- 常规路径不重画像素：PNG 解码后按无损流写进 PDF，画质与源文件逐像素一致No redraw on the normal path: the PNG is written into the PDF as a lossless stream, pixel-for-pixel the file you gave it
- 页面尺寸按图像像素在 96 dpi 下换算（px × 72 ÷ 96 点），横图自动横向The page is sized from the image pixels at 96 dpi (px × 72 ÷ 96 points), landscape automatically when it is wider than tall
- 唯一放弃无损的情形是超过 8192 px 的图——那时先等比重采样再嵌入，否则浏览器画不出来The one case that gives up losslessness is a side above 8192 px, which is resampled before embedding — otherwise the browser cannot draw it
- 解码失败或尺寸为 0 的坏图报该文件的错误，而不是给回一张空白 PDFA file that will not decode, or reports zero size, raises its own error instead of handing back a blank PDF
- 一批最多 200 个文件、单个 100 MB 上限；默认各自一个 PDF，勾选「合并为一份 PDF」后整批按列表顺序写成一份（每张一页，最多 200 页）Up to 200 files per batch and 100 MB each — one PDF per file by default, or one PDF for the whole batch in list order with “Merge into one PDF” ticked (one page per image, up to 200 pages)
如实说明的限制What it does not do
- 页面不是 A4：它就是那张图的尺寸，打印或拼册时要靠「适合页面」The page is not A4 — it is the picture’s own size, so printing and imposition rely on “fit to page”
- 默认不做多页合并——不勾选「合并为一份 PDF」时，一批 20 张得到 20 个 PDF；勾选后是一份 20 页的 PDF，任一张解码失败则整批不产出No merging by default — a batch of 20 images without the box ticked still gives 20 PDFs; with “Merge into one PDF” ticked they become one 20-page PDF, and if any image fails to decode nothing is produced at all
- 合并后每页仍是各自的像素尺寸，不会统一成 A4，不同尺寸的图在同一份 PDF 里各占一页Merged pages keep their own pixel dimensions rather than becoming A4, so differently sized images simply each take a page in the same PDF
- PDF 里没有文字层：源图本来也只有像素，搜索与复制都无从下手There is no text layer, because the source had only pixels; searching and copying have nothing to work on
- 动图 PNG（APNG）只留一帧：实测一份 Pillow 生成、浏览器可正常解出的双帧 APNG 能成功转成 PDF，产物是逐页位图、动画不保留，界面上同样没有丢帧提示。要保留动画就留在 PNG / GIF 本身，或走 HTML 那种只搬字节的路An animated PNG (APNG) contributes one frame: measured with a Pillow-written two-frame APNG that the browser decodes normally, the conversion completed and the artifact is a page-by-page bitmap with no animation left, and again no frame-loss notice appears. Keep motion by staying in PNG or GIF, or by taking the HTML route, which carries the bytes as they are
- 目标是 PDF 时输出参数面板不出现（面板只为图片目标显示），所以这里不能设 DPI 或最长边The output panel is not shown for a PDF target (it exists for image targets), so DPI and longest edge are not adjustable here
实操提示Working with it
- 结果文件名默认在源名后加日期与时间，模板可在偏好设置里改；一批多个文件时可一次打包成 ZIPNames default to the source name plus date and time, with the pattern editable in preferences; several files can come back as one ZIP
- 手上是一组要交出去的图？勾选「合并为一份 PDF」，整批按列表顺序装订成一份，文件名带 -merged；开关默认关闭，所以单张转换的行为与以前完全一样Handing over a set of images? Tick “Merge into one PDF” and the batch becomes one document in list order, named with a -merged suffix; the box is off by default, so a single conversion behaves exactly as before
- 需要「一张图一页 A4」的排法：先转 PDF 再在打印时选适合页面，或把图放进 HTML 走 HTML → PDF（那条按 A4 分页）For a “one image per A4 page” layout: print the PDF with fit-to-page, or place the image in HTML and take the HTML → PDF route, which paginates on A4
常见问题Questions people actually ask
能把多张 PNG 合成一个 PDF 吗？Can several PNGs become one PDF?
能，勾选「合并为一份 PDF」即可：整批都是 PNG / JPEG / WebP / BMP / GIF 且目标为 PDF 时，目标选择器下方会出现这个开关；勾上之后整批按列表顺序写成一份 PDF，每张一页（最多 200 页），文件名带 -merged。它默认关闭，所以一次只转一张时拿到的仍是一份单页 PDF；任意一张解码失败，整批都不产出，失败清单会点名是哪个文件。Yes — tick “Merge into one PDF”. The box appears when every file is a PNG / JPEG / WebP / BMP / GIF and the target is PDF; the whole batch then becomes one PDF, one page per image in list order (up to 200 pages), named with a -merged suffix. It is off by default, so a single image still gives one single-page PDF; if any image fails to decode, nothing is produced and the failure list names the file.
为什么打开 PDF 是一页超大的纸？Why does the PDF open as one enormous page?
因为页面尺寸就是图像尺寸（按 96 dpi 换算成点）。这是「不重画」这条路径的必然取舍：保住了像素，也保住了图的物理尺寸。Because the page is sized from the image itself (pixels to points at 96 dpi). That is the unavoidable trade of the no-redraw path: the pixels are preserved and so is the picture’s physical size.
转成 PDF 会变小吗？Does the PDF come out smaller than the PNG?
不会，通常还会略大：像素是无损重存进 PDF 流的，实测几张截图的产物是原 PNG 的 1.1–1.3 倍。要压体积请先在图片侧处理（换 WebP 或缩边长），再转 PDF。No, and it usually grows a little: the pixels go into the PDF stream losslessly, measured at 1.1x–1.3x the source PNG over several screenshots. Do the shrinking on the image side first — WebP or a shorter edge — then convert.
不需要账号，也不需要联网：装好扩展后点图标，在新标签页里打开工作台，文件从磁盘直接选。No account and no network: install the extension, click its icon, and the workbench opens in a new tab reading straight off your disk.
从 Chrome 应用商店安装Install from the Chrome Web Store 安装步骤Install steps GitHub 源码Source on GitHub