What types of differences are detected?

Text additions, deletions, and modifications are highlighted. Layout and image changes are also shown.

Can it compare engineering drawings or blueprints?

Yes — pick AEC / Blueprint mode. It runs a word-level text pass (dimensions, callouts, title-block revisions) alongside a masked pixel pass for geometry, so a relocated detail reads as "moved" and an in-place dimension change (Ø8 → Ø10) reads as one "modified" entry rather than a delete plus an insert. Each change is tagged with its sheet region and X/Y position.

Does this preserve bookmarks and form fields?

Yes. The output PDF inherits bookmarks and form fields from the chosen base document; the diff overlay is added as annotations.

What PDF versions are supported?

PDF 1.0 through 2.0 are diffed page-for-page. Encrypted files need to be unlocked first.

› PDF & Documents ›

Compare PDF Files

History

Support

Loft Browse tools

PDF & Documents 33 Image Tools 12 Dev Tools 6 Audio and Video 8 Cooking & Kitchen 2 Security & Privacy 4 Network & Sysadmin 2 Finance Tools 1 Open Anything 8

PDF & Documents View all

Add PDF Header & Footer
Annotate PDF
Compare PDF
Compress PDF
Crop PDF
Delete PDF Pages
Deskew PDF
Extract PDF Images
Extract PDF Pages
Extract PDF Tables
Extract PDF Text
Flatten PDF
HTML to PDF
Image to PDF
Merge PDF
OCR PDF
PDF Bates Numbering
PDF Bookmarks Editor
PDF Editor
PDF Grayscale
PDF Metadata Editor
PDF N-Up
Protect PDF
Redact PDF
Reorder PDF
Repair PDF
Resize PDF
Rotate PDF
Scan to PDF
Sign PDF
Split PDF
Unlock PDF
Watermark PDF

Image Tools View all

Barcode Generator
Color Palette Extractor
Color Picker
Compress Image to Exact KB
DPI Changer
ID Photo Maker
Image Compressor
Image Format Converter
Image Metadata Editor
Image Resizer
QR Code Generator
RAW to JPG Converter

Dev Tools View all

CSV to JSON
Hash Generator
IP Subnet Calculator
Log Query Workbench
Subnet Planner
UUID Generator

Audio and Video View all

Audio Converter
Audio Tag Editor (ID3)
Compress Audio
Extract Audio from Video
Remove Audio from Video
Video Compressor
Video Converter
Video to GIF

Cooking & Kitchen View all

Canning Calculator
Sourdough Calculator

Security & Privacy View all

EVTX Explorer
File Encryption
Identity Inspector
Secure Note Sharing

Network & Sysadmin View all

PCAP Analyzer
Serial Console

Finance Tools View all

Chart Overlay Studio

Open Anything View all

3MF Viewer
DXF Viewer
Gerber Viewer
GLB / glTF Viewer
OBJ Viewer
PLY Viewer
STEP Viewer
STL Viewer

Compare PDF Tip

Exclusion zones for noise

Drag a rectangle to mark a region as ignore — useful for headers, page numbers, and timestamps that change but do not matter.

More tools like this

Keyboard shortcuts

Open search Ctrl +K
Open search (alt) /
Close any modal / drawer Esc
Show this help ?
Move focus forward Tab
Move focus back Shift +Tab

Press ? anytime to reopen.