合并多个 PDF、压缩过大的文件、PDF 转 Word/图片、拆分页面、发票排版打印……本文整理日常高频 PDF 需求的做法，并说明为什么优先选择浏览器本地处理。
合同、发票、证件类 PDF 往往含敏感信息。上传到不明服务器的在线转换存在泄露风险。选择「浏览器本地处理」的工具，文件不离开你的设备，断网也能用，是处理机密 PDF 更稳妥的方式。
PDF 体积多来自高分辨率图片。合理做法是降低内嵌图片分辨率与质量（一般 150dpi 足够屏幕与打印阅读）、去除冗余字体与元数据、移除未使用对象。先试「中等压缩」，不满意再逐步加强。
365Lab PDF 工具箱 提供数十种免费 PDF 操作，合并、压缩、转换、拆分、页面管理一应俱全，全部在浏览器本地完成。报销场景可配合 发票助手 把多张电子发票排版拼到 A4 打印，整理命名再用 文件重命名 批量处理。
适度压缩（约 150dpi）阅读与打印基本无感；过度压缩才会影响清晰度，建议按用途分档尝试。
纯文字类转换较准；复杂排版、扫描图会有偏差，扫描件需先做 OCR。
选择本地处理的工具时，文件不上传服务器，全程在浏览器内完成，更安全。
Merging contracts, shrinking large PDFs, converting to Word/images, splitting pages, arranging invoices — here are the common jobs and why local processing is safer.
Contracts, invoices and ID PDFs are sensitive. Uploading them to unknown servers risks leaks. A browser-local tool keeps files on your device and works offline — safer for confidential PDFs.
Most PDF size comes from embedded images. Lower their resolution/quality (about 150dpi is fine for reading and print), subset fonts, strip metadata and unused objects. Start with medium compression and increase only if needed.
The 365Lab PDF Toolbox offers dozens of free PDF operations — merge, compress, convert, split and page management — all in your browser. For expenses, pair with Invoice Helper to arrange invoices onto A4, and File Renamer to batch-name them.
At a sane ~150dpi, reading and printing are barely affected; only heavy compression degrades quality.
Text-heavy docs convert well; complex layouts and scans drift — run OCR on scans first.
With local tools, files never upload — everything happens in the browser.
