"Editing a PDF" can mean six completely different things: merging several into one, converting photos into a PDF, pulling pages out as images, shrinking the file's size, adding a watermark, or splitting it into parts. Most people search "online PDF editor" when they really only need one of these six tasks, and end up on bloated tools that ask for sign-up for something that should take ten seconds.
This guide is a quick map: which task you need and which free tool solves it, all without installing software or uploading the file to a server.
1. Convert images to PDF
If you have photos of a document (or screenshots) and need to bundle them into a single PDF to send or print, there's no need to open Word or an image editor. Upload the photos, reorder them by dragging, pick A4 or Letter size and margins, and download the PDF. Works with JPG, PNG and WebP.
Tool: images to PDF.
2. Merge several PDFs into one
For combining chapters, appending documents to a contract, or joining pages scanned separately. Upload the PDFs, order them, and generate the combined document, no watermark and no recompressing the content.
Tool: merge PDF.
3. Split a PDF into parts
The opposite of merging: extracting a specific page range, splitting a large document into manageable chunks, or separating every page into its own file.
Tool: split PDF.
4. Convert PDF to images
When you need each page as a separate JPG or PNG, for example to upload them to a site that doesn't accept PDFs, or to insert them into a presentation. You can choose 1x, 2x or 3x resolution depending on whether the destination is screen or print.
Tool: PDF to images.
5. Compress a PDF
When the file is too heavy to email or upload to a form with a size limit. Compression removes unnecessary metadata and optimizes the file's internal structure, without visibly losing content quality.
Tool: compress PDF.
6. Add a watermark
To protect a document before sharing it as a draft, mark sample copies, or identify a file's origin. It's added as overlaid text on every page, with configurable position, opacity and color.
Tool: PDF watermark.
Why all of this works without uploading your file
All these operations are processed directly in your browser with libraries like pdf-lib, without going through any server. That matters especially with PDFs because they almost always contain something you'd rather not share with third parties: contracts, payslips, invoices, internal reports. The file opens, transforms and downloads, all on your own machine.
How to quickly pick the right tool
If you're torn between several, ask yourself what changes in the final result:
- Does the number of pages change? → merge or split.
- Does the file format change (PDF ↔ image)? → images to PDF or PDF to images.
- Does the size change without changing the visible content? → compress.
- Is something visible added on top of existing content? → watermark or page numbers.
- Does the order or orientation of existing pages change? → reorder or rotate.
Frequently asked questions
Do I have to pay for any of these tools? No, all of them are free, with no tool-added watermark and no usage limit.
Do I need to create an account? No, they're used directly with no sign-up.
Can I chain several operations? Yes: for example, compress a PDF and then add a watermark to it, downloading and re-uploading the result between steps.
Does it work the same on mobile? Yes, though for very large documents or ones with many pages, a computer processes faster.
Explore the 6 PDF tools on this site in the PDF tools hub: convert, merge, split, compress and watermark, all free and 100% in your browser.