How to Compress a PDF to 100KB (or Any Size Limit) for Online Forms
Get a PDF under 100 KB, or any upload limit, in minutes: the right compression settings, what to do when it won't shrink, and how to keep text readable.
Compress & Optimize · 12 guides
Compress and Optimize PDFs and Images
Upload limits are the most common reason a document gets stuck: 100 KB for an exam form, 2 MB for a job portal, 25 MB for an email attachment. These guides show how to hit a specific size, which settings cost quality and which don't, and what to do when a file simply refuses to get smaller.
12 articles in Compress & Optimize
How to Compress a PDF to 1MB or Less (Resumes, Reports, Forms)
Compress a PDF to 1 MB without blurry text: shrink the photos at the source, pick the gentlest setting that works, then test the links before sending.
How to Compress a PDF to 200KB, Even a Multi-Page Scan
Compress a PDF to 200 KB even when it holds several scanned certificates: work out a per-page budget, merge before compressing, and keep stamps legible.
How to Reduce PDF File Size: 7 Methods That Actually Work
How to reduce PDF file size seven ways: online compression, grayscale scans, cutting or splitting pages, smaller Word exports and Mac or iPhone tools.
How to Compress a PDF on Mobile (Android and iPhone)
Compress a PDF on mobile without installing an app: the browser route for Android and iPhone, the iPhone's built-in Preview option, and photo-based PDFs.
How to Compress a PDF to 500KB for Online Applications
Compress a PDF to 500 KB even when it bundles phone photos, a scanned form and a certificate: shrink each part the right way, merge, then compress once.
How to Compress a PDF Without Losing Quality
How to compress a PDF without losing quality: the lossless route that changes no pixels, and the gentlest compression level for screen, email or print.
How to Compress a Scanned PDF and Keep It Readable
Compress a scanned PDF the smart way: the scan settings that save the most space, what each compression level does to scans, and why OCR must come first.
How to Convert a PDF to Black and White (Grayscale) for Free
Convert a PDF to black and white for a smaller file or cheaper printing: grayscale vs pure black and white, a free online method, and when to keep colour.
PDF Too Large to Email? 5 Ways to Send It Anyway
PDF too large to email? See the real Gmail and Outlook limits, why a 20 MB file can still bounce, and five fixes: compress, split, cloud links and more.
How to Reduce PDF Size on a Mac (Without Preview's Blurry Results)
Reduce PDF size on a Mac with Preview's Quartz filter, a gentler custom filter made in ColorSync Utility, or an online compressor that shows the result first.
Why Is My PDF So Large? Common Causes and Quick Fixes
Why is your PDF so large? A quick KB-per-page check finds the cause, from big scans and full-size photos to heavy fonts and old edits, plus the fix for each.
Try the tools
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- Compress PDFShrink PDF file size while keeping the quality you need.Use it free →
- Image CompressorShrink image file size with a quality slider and a live before/after size.Use it free →
- Image ResizerResize images to exact dimensions without accidental distortion.Use it free →
- Split PDFExtract pages or split a PDF apart.Use it free →