What Is PDF Merge?
PDF Merge is a tool that combines multiple PDF files and images into a single PDF document. Upload your files, reorder individual pages, select which pages to include, rotate pages, and merge them — all directly in your browser. This tool runs 100% client-side. Your files are never uploaded to any server.
It supports PDF, JPEG, PNG, and WebP files with per-file size limits (PDF 50MB, JPEG 10MB, PNG 20MB, WebP 10MB) and a 200MB total limit. Features include page thumbnail previews, drag-and-drop reordering, per-page selection and range input, rotation, deletion, custom output filename, a real-time progress bar, merged PDF preview, and IndexedDB persistence across page refreshes.
How to Use This Tool
Add Your Files
Click Add Files to select PDFs or images (JPEG, PNG, WebP), or drag and drop them onto the input area. Per-file limits: PDF 50MB, JPEG 10MB, PNG 20MB, WebP 10MB. Total limit: 200MB.
Organize & Select Pages
Drag page thumbnails to reorder them. Select or deselect pages with checkboxes, use Select All / Deselect All, type a page range (e.g. 1-4, 3-8), rotate pages on hover, or delete unwanted pages.
Set Filename & Merge
Enter a custom filename in the top bar. Click Merge to combine selected pages. A progress bar shows real-time status. The merged PDF appears in the Output preview.
Download
Once merged, click Download to save the PDF. Your files and merged output persist across page refreshes via IndexedDB. Click Clear All to remove everything.
Features Explained
Drag & Drop Upload
▼
Drag PDF or image files from your file explorer directly onto the input area. The area highlights when files are dragged over it. You can also click Add Files to open a file picker. Multiple files can be added at once.
Page Thumbnail Previews
▼
Every page of every uploaded PDF is rendered as a visual thumbnail using pdf.js. Images (JPEG, PNG, WebP) are shown directly. All thumbnails are displayed at a uniform size with the filename and page number below each one.
Per-Page Drag & Drop Reordering
▼
Drag individual page thumbnails to reorder them freely across all files. This lets you interleave pages from different documents or rearrange pages within a single document.
Page Selection & Deselection
▼
Click the checkbox on any page thumbnail to include or exclude it from the merged output. Use Select All and Deselect All buttons in the toolbar for bulk actions. Deselected pages appear faded. At least 2 pages must be selected to merge.
Page Range Input
▼
Type a range like "1-4, 3-8" in the toolbar and click Apply to select only those pages by their position. This is faster than clicking individual checkboxes for large documents.
Page Rotation
▼
Hover over a page thumbnail and click the rotate button to rotate it 90 degrees clockwise. Click multiple times for 180 or 270 degrees. Rotation is applied during the merge process using pdf-lib.
Page Deletion
▼
Hover over a page thumbnail and click the red delete button to permanently remove it. If all pages of a file are deleted, the file is automatically removed. This action cannot be undone.
Image Support (JPEG, PNG & WebP)
▼
Add JPEG, PNG, and WebP images alongside PDFs. Each image is scaled to fit an A4-sized page (landscape-aware) and centered. WebP images are converted to JPEG at merge time since PDF does not natively support WebP.
File Size Limits
▼
Per-file limits protect your browser from running out of memory: PDF 50MB, JPEG 10MB, PNG 20MB, WebP 10MB. The total combined limit across all files is 200MB. Files exceeding these limits are rejected with a clear error message.
Custom Output Filename
▼
Enter a custom name in the Filename field in the top bar. The .pdf extension is added automatically if omitted. If left empty, the file downloads as "merged.pdf".
Separate Merge & Download
▼
Merge and Download are separate actions. Click Merge to process the selected pages — the result appears in the Output preview. Click Download when ready to save the file. This lets you verify the output before downloading.
Progress Bar & Status
▼
During merging, a progress bar shows percentage complete and which page is being processed. After merge completes, the bar stays visible at 100% in green showing the page count and file size of the output.
Merged PDF Preview
▼
The Output panel renders the merged PDF page by page with drop shadows on a gray background, similar to how PDFs appear in a browser viewer. Scroll to inspect every page before downloading.
IndexedDB Persistence
▼
Your uploaded files, page selections, rotations, and merged output are saved to your browser’s IndexedDB. Refreshing the page restores everything exactly as you left it. Click Clear All to remove all stored data.
Who Is This Tool For?
Office Workers
Combine reports, invoices, contracts, and scanned documents into a single PDF for sharing or archiving.
Students
Merge lecture notes, assignments, research papers, and scanned handwritten pages into one submission file.
Freelancers
Combine proposals, contracts, portfolios, and invoices into a single professional document for clients.
Legal Professionals
Merge case documents, exhibits, filings, and signed agreements into organized PDF bundles.
Real Estate Agents
Combine property listings, contracts, disclosures, and inspection reports into complete transaction packages.
Designers
Merge mockups, mood boards, and exported artboards with project documentation into client deliverables.
Supported File Types
| Format | Extensions | Max Size | How It Works |
|---|---|---|---|
| 50MB | Pages copied directly via pdf-lib, preserving quality and vectors | ||
| JPEG | .jpg, .jpeg | 10MB | Scaled to fit A4, centered, embedded via pdf-lib |
| PNG | .png | 20MB | Scaled to fit A4, centered, transparency preserved |
| WebP | .webp | 10MB | Converted to JPEG via canvas, then scaled and embedded |
Tips for Merging PDFs
Drag thumbnails to reorder
Drag any page thumbnail to a new position. You can interleave pages from different files freely.
Use page range for large documents
For PDFs with many pages, type a range like "1-4, 3-8" instead of clicking individual checkboxes.
Rotate before merging
If a scanned page is sideways, hover over its thumbnail and click the rotate button. The rotation is applied during the merge.
Mix images and PDFs freely
Add JPEG, PNG, or WebP images alongside PDFs. Each image is scaled to fit an A4 page and centered in the merged output.
Preview before downloading
After clicking Merge, check the Output panel to verify the result. The merged PDF is rendered page by page so you can scroll through it.
Your work persists
Files and merged output are saved to IndexedDB. Refresh the page and everything is restored. Click Clear All to remove all stored data.
Privacy & Security
This tool runs 100% in your browser. Your PDF files and images are never uploaded to any server. All merging, rendering, and processing happens locally using JavaScript, pdf-lib, and pdf.js.
Files are stored in your browser's IndexedDB so they persist across page refreshes. This data lives only on your computer and is never transmitted. Click Clear All to remove all stored files and merged output immediately. No cookies are used, no analytics track your files, and no third-party services have access to your documents.