离线 · 无上传 · 浏览器本地完成Offline · no uploads · runs in the browser
Excel 转 WebP——离线、多表分节、按 A4 出图Excel to WebP offline — sheets, A4 pages
和 Excel→JPG 是同一条三步链，只有终点不同：`xlsx>html` + `html>pdf` + `pdf>webp`（基线现读）。第一步由 SheetJS 把工作表写成 HTML 表格，**读的是文件里已经算完存下的值**——公式不会被重新求值，也不会被执行；单元格样式、列宽、底色与条件格式**完全不进这份中间 HTML**（读取没要 `cellStyles`），所以图里的底纹只可能来自渲染器的默认样式，而不是你在工作表里看到的那套配色。多张工作表时中间文档里会是多张表、各带一个标题（这与「多张表会让 JSON 那一步变成分组对象」是两回事——这条路不经过取表成 JSON 的那一步）。第二步由浏览器排在 **800 px 版心**、按 **A4** 分页，每页作为 **PNG 无损切片**写进 PDF；第三步由 pdf.js 逐页画到白底画布、`encodeCanvas` 编成 WebP，因此**整条链只量化一次**，质量与目标尺寸只作用在终点。三条边界照实写：**宽度没有闸**，超出内容区的右侧列被裁掉而不是换行；**高度有闸**，超过 32768 px 时渲染那一步明确报 `errors.renderTooTall`（Excel→PDF 同一道），长表请分批；这条链的中间 PDF 因同一道闸排不到几百页，所以出图那一步的页数上限在这里碰不到。没有选页参数（页码选择只在源是 PDF 时存在），产物是图片、字不能被程序读回。全程只有 storage 权限、不联网。This is Excel to JPG’s chain with a different endpoint: `xlsx>html` + `html>pdf` + `pdf>webp`, read live from the baseline. Step one has SheetJS write the sheets as HTML tables and it reads **the values already computed and stored in the file** — no formula is re-evaluated and none is executed; cell styles, column widths, fills and conditional formatting **do not enter that intermediate HTML at all** (the reader never asks for `cellStyles`), so any shading in the image can only come from the renderer’s defaults, not from the palette you see in the workbook. With several sheets the middle document holds several tables, each under a title — which is a different matter from «several tables turn into a grouped object at the JSON step», since this chain never passes that step. Step two lets the browser set the HTML into the **800 px measure** and paginate it on **A4**, writing each page into the PDF as a **lossless PNG slice**; step three has pdf.js draw pages onto a white canvas and `encodeCanvas` them into WebP, so **exactly one quantisation happens** and quality or target size act only there. Three boundaries, stated: **nothing gates width**, so columns past the content box are clipped rather than reflowed; **height is gated**, past 32768 px the render step fails with `errors.renderTooTall` (Excel to PDF carries the same ceiling), so split long sheets; and because that ceiling keeps the intermediate PDF from reaching hundreds of pages, the image step’s page cap is unreachable here. There is no page-range control (it exists only when the source is a PDF), and the artifact is a picture whose words a program cannot read back. All of it on the storage permission, with no network.
这条链路怎么走How the route runs
Excel (.xlsx)Excel (.xlsx) HTMLHTML PDFPDF WebPWebP
共 3 步，由扩展的路径搜索自动选出，中间产物不落盘。3 steps, chosen by the extension's own path search; intermediate results never touch the disk.
会保留什么What carries over
- 读的是算完的值：公式不重算也不被执行，格子里存着什么就画什么It reads computed values: no formula is re-evaluated or executed, and each cell draws what it stores
- 多张工作表都进图，每张前有标题，且这条路不经过「只吃数组」那一步Every sheet reaches the image, each under a title, and this chain never passes the arrays-only step
- 整条链只量化一次：中间是 PNG 无损切片，质量与目标尺寸只作用在 WebP 终点One quantisation on the chain: the middle is lossless PNG slices, quality and target size act only on the WebP endpoint
- 按 A4 逐页出一页一张 WebP，多页打包成 ZIP、条目按页顺序命名Paginated on A4, one WebP per page; several pages arrive as a ZIP numbered in page order
- 一批最多 200 个文件、单个 100 MB，与其他路线共用同一道闸门Up to 200 files per batch and 100 MB each — the same gate every other route shares
如实说明的限制What it does not do
- 宽度没有闸：超出约 800 px 版心的右侧列被裁掉而不是换行，宽表请先拆列Nothing gates width: columns past the roughly 800 px measure are clipped, not wrapped — split a wide sheet first
- 高度有闸：排版超过 32768 px 时明确报 `errors.renderTooTall`，长表要分批（Excel→PDF 同一道闸）Height is gated: past 32768 px of laid-out page it fails with `errors.renderTooTall`, so long sheets need splitting (Excel to PDF shares that ceiling)
- 单元格样式与条件格式都不出现：图里的底纹只来自渲染默认样式Cell styles and conditional formatting never appear: any shading in the image comes from the renderer’s defaults
- 产物是图片：格子里的字选不中、不能被程序读回；要数据走 Excel→CSV / JSONThe artifact is a picture: cell text cannot be selected or read back by a program — take Excel to CSV or JSON for data
- 没有选页这一步：分页来自排版，页码选择只在源是 PDF 时存在There is no page-range step: pagination comes from layout, and the range control exists only when the source is a PDF
实操提示Working with it
- 要一份多页文档：Excel→PDF，中间那份 PDF 就是终点、切片无损For a multi-page document: Excel to PDF, where that intermediate PDF is the destination
- 要最通用的分页快照：Excel→JPG 是同一条三步链，终点换成 JPEGFor the most universally readable paginated snapshot: Excel to JPG, the same chain ending in JPEG
- 要结构与文字都留住：Excel→HTML 或 Excel→Markdown，那里表格还是表格To keep structure and words: Excel to HTML or Markdown, where the table stays a table
常见问题Questions people actually ask
多个工作表会一起出图吗？Do all the sheets come out together?
会——每张表前有一个标题，全部排进同一份中间 HTML，再按 A4 逐页成图；页数多的结果打包成 ZIP，条目按页顺序命名。这与「Excel→CSV / JSON 那几页在多张表时的规则」无关，因为这条链不经过取表成 JSON 的那一步。They do: each sheet is preceded by a title inside one intermediate HTML, then paginated on A4 into images; long results arrive as a ZIP numbered in page order. This has nothing to do with the rules on the Excel to CSV / JSON pages, because this chain never passes the table-to-JSON step.
我在工作表里看到的配色会跟着进图吗？Does the colour scheme I see in the workbook come along?
不会。第一步读的是单元格的值，不取样式，所以底色、字体、条件格式的颜色都不进中间那份 HTML；图里若有底纹，那是渲染器默认样式画出来的。要保住观感，请在 Excel 里导出 PDF 再走 PDF→WebP。No. Step one reads values, not styles, so fills, fonts and conditional-formatting colours never enter the intermediate HTML; any shading in the image is what the renderer’s defaults produce. To keep the look, export a PDF in Excel and take PDF to WebP.
为什么右边几列不见了？Why did the columns on the right disappear?
因为这条链把 HTML 排在约 800 px 版心里，而宽度方向没有任何检查：超出的列是被裁掉的，不会折到下一行，也不会报错。拆列、或改走 Excel→PDF / Excel→HTML 自己在阅读器里缩放，是三种实际解法。Because the HTML is set into a roughly 800 px measure and nothing checks width: overflowing columns are clipped, not wrapped, and no error is raised. Split the columns, or take Excel to PDF / HTML and scale in a reader.
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
要把它压到指定体积？Need it under a target size? The 图片压缩工具image compressor可以在浏览器里重编码 PNG / JPEG / WebP。 re-encodes PNG / JPEG / WebP in the browser.