JotTool provides free online JSON Formatter and Text Diff tools. All tools run entirely in your browser — no server uploads, no sign-ups, no data collection.

Are JotTool tools free?

Yes, all tools on JotTool are completely free with no hidden costs, no premium tiers, and no usage limits.

Is my data safe with JotTool?

Yes. All processing happens client-side in your browser using JavaScript. Your files, text, and data are never uploaded to any server, ensuring complete privacy.

Do I need to create an account?

No. JotTool requires no sign-ups, no downloads, and no software installation. Just open the page and start using the tools instantly.

JotTool是什么？在线JSON格式化工具怎么用？

JotTool 是一个提供免费在线 JSON 格式化和文本对比工具的在线平台。所有工具完全在浏览器中运行，无需上传数据到服务器，无需注册登录，不收集任何用户数据。

JotTool的工具免费吗？

是的，JotTool 上的所有工具完全免费，没有隐藏费用，没有高级版本，没有使用次数限制。

在线JSON格式化怎么用？数据安全吗？

打开 JotTool 网站即可使用 JSON 格式化工具，支持 JSON 美化、压缩、校验、排序等功能。所有处理都在浏览器本地完成，数据不会上传到任何服务器，完全保障您的隐私安全。

What PDF tools are available on JotTool?

JotTool provides 7 free PDF tools that all run in your browser: Merge PDF (combine multiple files into one), Split PDF (extract specific pages), Image to PDF (convert JPG/PNG images to PDF with drag-and-drop reordering), Add Watermark (single or tiled watermark with position, font size and density controls), PDF to Images (export pages as individual PNGs or stitch into one long image), Rotate Pages (fix orientation for scanned documents), and Add Page Numbers (with left/center/right positioning and adjustable font size).

Is my PDF data safe? Are files uploaded to a server?

Yes, your data is completely safe. All PDF processing happens entirely in your browser using JavaScript libraries (pdf-lib, pdfjs-dist). Your files are never uploaded to any server, ensuring complete privacy for your documents. You can verify this by checking your network tab — no PDF data leaves your device.

Are these PDF tools free? Any limitations?

Yes, all PDF tools on JotTool are completely free with no usage limits, no sign-ups required, and no watermarks added to your output files. There are no file size limits and no daily usage caps.

How to merge multiple PDF files into one?

Use the Merge PDF tool: upload multiple PDF files, drag to reorder them if needed, then click merge to combine them into a single PDF file. Download the merged result instantly.

How to add a watermark to PDF? Can I control the position?

Use the Add Watermark tool: upload your PDF, enter watermark text, choose between single watermark or tiled (repeated) mode. For single mode, select position: center, top-left, top-right, bottom-left, or bottom-right. Adjust font size (12-120px), opacity, and for tiled mode, control the density. Supports Chinese and other non-Latin characters.

How to convert PDF to images? Can I get a long stitched image?

Use the PDF to Images tool with two modes: Single Page mode exports each page as individual PNG with select-and-download or ZIP download; Long Image mode stitches all pages vertically into one continuous image. Preview is generated instantly on upload.

JotTool有哪些PDF工具？

JotTool 提供 7 个免费在线PDF工具，全部在浏览器中运行：PDF合并（将多个文件合为一个）、PDF拆分（提取指定页面）、图片转PDF（支持JPG/PNG，可拖拽排序）、添加水印（支持单个/平铺模式，可调位置、字体大小和密度）、PDF转图片（导出单页PNG或拼长图）、旋转页面（修正扫描件方向）、添加页码（支持左/中/右位置和字体大小调节）。

PDF文件会上传到服务器吗？数据安全吗？

不会。所有PDF处理完全在浏览器本地完成，使用JavaScript库（pdf-lib、pdfjs-dist）进行处理。您的文件不会上传到任何服务器，完全保障隐私安全。您可以通过浏览器开发者工具的网络面板验证——没有任何PDF数据离开您的设备。

如何给PDF添加水印？支持中文水印吗？

使用「添加水印」功能：上传PDF后输入水印文字，选择单个水印或平铺水印模式。单个水印支持5个位置（中间、左上、右上、左下、右下），可调节字体大小（12-120px）和透明度。平铺水印可调节密度。完全支持中文及其他非拉丁字符水印。

PDF转图片怎么拼长图？

使用「PDF转图片」功能，选择「拼长图」模式，系统会自动将所有PDF页面纵向拼接成一张完整的长图PNG。也可以切换「单页图」模式，单独选择需要的页面打包ZIP下载。

PDF Tools - Merge, Split, Watermark, Rotate & Convert PDF Online (Free Tool)