PDF Compare Tool Compare metadata, text differences, and pages side by side
Upload two PDFs to compare their metadata, review an AI-generated summary of text differences, and inspect corresponding pages side by side with synchronized scrolling.
Your PDF files stay in your browser. Metadata comparison and page rendering happen locally. If you use the AI summary, the extracted text is sent to the configured AI provider for processing; the PDF files themselves are not uploaded.
The comparison console
Upload both PDFs, then compare.
Private by design
Metadata comparison and page rendering happen in your browser. If you use the AI summary, only extracted text is sent to the configured AI provider; this WordPress handler does not intentionally save that text.
PDF File 1
Drag & drop or click to upload
AI summary text limit: up to 200,000 extracted characters per PDF.PDF File 2
Drag & drop or click to upload
AI summary text limit: up to 200,000 extracted characters per PDF.Analyzing PDFs, please wait...
Metadata Comparison
Content Summary
Side-by-Side Viewer
Finish the job
Use your own API key
The configured AI providers could not generate the summary. You can continue by providing your own API key from either provider below.
- Go to aistudio.google.com/app/apikey
- Sign in with your Google account
- Click Create API key and copy it
Free tier: a generous number of requests per day at no cost. Paid tiers are also available for heavier use.
Three ways to compare what changed
Metadata, text, and page rendering are reviewed separately.
What it does
- Compares 13 metadata fields — file size, page count, author, dates, and more — with mismatches instantly color-coded.
- Generates an AI summary of text differences from the extracted PDF text.
- Shows both PDFs page by page, side by side, with scrolling synced between them.
- Lets you use your own API key if the configured AI providers are unavailable.
What it doesn't do
- Doesn't draw pixel-level highlight boxes around exact changed regions — the visual view is for eyeballing pages side by side, not automated visual diffing.
- Doesn't summarize extremely long documents in one pass — very large PDFs may need to be split first.
- Doesn't open password-protected PDFs without the correct password.
Compare two PDFs in three ways
Upload both files, run the comparison, then review metadata, text differences, and pages side by side.
Upload both PDFs
Drag in File 1 and File 2, or click either box to browse.
Click Compare PDFs
Metadata is compared, text is extracted, and an AI summary is requested as part of the comparison.
Review the results
Check color-coded metadata, read the AI summary, or browse pages side by side.
Export if needed
Download the full report as TXT, or just the metadata table as CSV.
Where PDF Compare fits
And where a different approach serves you better.
| Use case | Why | Fit |
|---|---|---|
| Checking if a document's properties changed | Every metadata field is compared and mismatches are instantly visible. | Strong fit |
| Getting a quick summary of what changed | The AI summary reads both documents and describes the differences in plain language. | Strong fit |
| Manually eyeballing layout or formatting changes | Synced side-by-side scrolling makes visual differences easy to spot. | Good fit |
| Getting exact pixel-level change boxes | This is a visual side-by-side view, not automated pixel-diff highlighting. | Not a fit |
| Comparing a password-protected PDF | The file needs to be unlocked before it can be opened here. | Use Unlock PDF first |
How the AI summary fallback works
A single AI provider is a single point of failure. This has three layers before it gives up.
The site tries its own Gemini key first
The site tries its configured Gemini provider first, so no API key is required when that provider is available.
If that's unavailable, it tries OpenRouter next
If the Gemini request fails, the site can try the configured OpenRouter provider next, subject to its availability and limits.
Only if both are down does it ask you for a key
If both configured providers fail, you can provide your own API key. This tool does not intentionally store that key in WordPress.
When something doesn't work as expected
What's actually happening, and the fastest way through it.
"Please upload a valid PDF file"
The selected file isn't recognized as a PDF.
Make sure the file is a readable PDF and is not damaged or password-protected.
A popup asks for my own API key
The site's own AI providers are both temporarily unavailable or rate-limited.
Get a free key from either provider using the in-popup instructions, or try again later.
"Rate limit exceeded" message
You (or everyone using this tool) reached the hourly or daily cap for AI summaries.
If the AI provider is unavailable, you can supply your own key. If you have reached this tool's request limit, wait for the limit window to reset.
The two PDF pages don't line up
The documents have a different number of pages, or content shifted earlier in one file.
Use the page navigation to browse each document's pages independently.
Not a valid PDF
Why: File isn't recognized as PDF.
Fix: Make sure the file is a readable PDF and is not damaged or password-protected.
Asked for my own key
Why: Site's AI providers unavailable.
Fix: Get a free key or try later.
Rate limit exceeded
Why: Hourly/daily cap reached.
Fix: Wait, or use your own key.
Pages don't line up
Why: Different page counts.
Fix: Browse each side independently.
Getting a clear, useful comparison
Use the metadata, AI summary, and visual viewer together for a clearer review.
Start with the metadata cards
They're the fastest way to catch an obviously wrong file before reading a longer AI summary.
Use the visual viewer for layout changes
Formatting and image differences are often easier to spot by eye than to describe in a text summary.
Download the TXT report for records
Save the metadata and generated AI summary as a local TXT file for your records.
Keep a free key handy for busy periods
If the configured AI providers are unavailable, your own key can provide an alternative provider connection.
PDF Compare FAQs
Start with the first two if you're wondering about privacy or reliability.
Are my PDF files uploaded to a server?
No, the PDF files themselves are not uploaded by this page. Metadata comparison and page rendering happen in your browser. If you use the AI summary, extracted text is sent to the configured AI provider for processing.
What happens if the AI summary can't be generated?
The site tries its configured Gemini provider first, then OpenRouter if Gemini fails. If both configured providers fail, you can provide your own API key. This tool does not intentionally store that key in WordPress.
Is there a limit on how many comparisons I can run?
The AI summary step has hourly and daily limits per IP and site-wide. Metadata comparison and page rendering run in your browser and do not use the AI endpoint.
Can I export the comparison results?
Yes — download a full text report (metadata plus the AI summary) as a TXT file, or just the metadata table as a CSV.
Does it work on password-protected PDFs?
Not directly — a password-protected PDF needs to be unlocked first before it can be opened and compared here.