Work in batches
Every PDF remains independent: remove an item, compress one document, or process the entire selection at once.
MINI TUTORIAL · PDF LAB
Quick tutorial: compress your batch in four steps
- 1
1. Build the batch
Drop every PDF into the workspace. Files stay separate, so you can remove anything that should not be compressed.
- 2
2. Choose the balance
Use Balanced for normal documents, Smallest file for sharing, or High quality for scans where visual readability matters.
- 3
3. Check the forecast
The panel shows current size, an estimate based on profile and JPEG quality, and the expected reduction. It updates as you change controls.
- 4
4. Compress and download
Process the full batch or one file at a time. Compare thumbnails and actual sizes, then download PDFs separately or in one ZIP.
GUIDE · PDF LABHow to compress PDF batches locally
Reduce large files while keeping control of the batch
Add every document that needs reduction, choose a profile, and compare each result before downloading separate files or one ZIP. Processing stays in your browser.
Choose a profile
Balanced fits most documents. Smallest file prioritizes sharing and storage. High quality preserves more detail in scans and images.
Compare results
Cards show the original and compressed first page plus the size change. A PDF that is already optimized may become larger.
Know the limitation
Reduction rebuilds visual pages as JPEG. It works best for scans and image PDFs; selectable text, vectors, links, forms, and signatures may be flattened.
Frequently asked questions
Are my PDFs uploaded to a server?
No. Reading, rendering, compression, and ZIP creation happen locally in this browser on your device.
Why can the final size differ from the estimate?
The estimate uses current size, profile, and JPEG quality. The actual result depends on image count, resolution, colors, pages, and how the original PDF was created.
Which profile should I choose?
Start with Balanced. Use Smallest file when a destination has an upload limit, and High quality for scans, photos, or detail-sensitive material.
Will text remain selectable?
Not always. The tool rebuilds visual pages as JPEG, so selectable text, vectors, links, forms, and signatures may be flattened.
Why can a PDF become larger?
An already optimized or visually simple PDF may not benefit from JPEG rebuilding. The file card warns when the result is larger.
Can I download every file at once?
Yes. Once processing finishes, use Download ZIP to get all compressed PDFs in one download.
Tip: keep the original when the PDF has a digital signature, editable form, important links, or vector art that must remain selectable.
Collapse complete guide
Ecosystem Highlights
01 // 029Finance Lab
Compound Interest Calculator
Build real-time financial projections, edit contributions directly on the chart, and see how each decision changes the future.
PDF Lab
Watermark PDF
Edit text or images over real pages with smart placement by format and a local batch.
PDF Lab
Split PDFs
Split PDF batches by range, individual page, or chunks and download the results as ZIP.
PDF Lab
PDF to Images
Convert PDF pages to local PNG or JPEG images in batches with ZIP download.
Image Lab
Image Resizer
Resize image batches by pixels, percentage, or maximum limits. Adjust aspect ratio, framing, and output format.
Calculators
Rule of Three Calculator
Calculate direct and inverse proportions for price, quantity, time, distance, and percentages.
Development
JSON Formatter
Format, validate, and minify JSON to review API responses, configuration files, and integrations.