Compress PDF Files Online
Reduce PDF file size online for portals, email, storage, and document sharing. Slim Files focuses on practical compression while keeping the workflow simple and secure.
Use this when the PDF is finished but still too large for a portal, inbox, or document handoff.
- Best for scanned paperwork, proposals, exported decks, and image-heavy PDFs.
- Treat strict limits like 1 MB or 500 KB as target ranges, not guaranteed outputs.
- If the file barely shrinks, the source scan or embedded images are usually the real constraint.
The biggest PDF savings usually come from embedded images, not from text-heavy pages that were already efficient.
Drop files or click to upload
Max file size: 50MB. Supports PDF files.
Workflow safeguards
Validated inputs
Files are checked by content before processing begins.
Metadata stripping
EXIF and producer fields are removed from processed outputs by default.
Temporary retention
Files are purged from disk within 1 hour.
Upgrade for API access and larger workflows
Paid plans are better for recurring teams, larger file batches, and authenticated API processing. The free workflow above stays centered on the web tool first.
Compare PlansWhat this pdf compressor is best for
This PDF compressor is designed for the moments when a document is technically finished, but still too large to send, upload, or archive comfortably. That is common with scanned paperwork, image-heavy proposals, exported presentations, and multi-page attachments that need to fit within strict portal or mailbox limits.
The biggest savings usually come from PDFs that contain embedded images. Text, vector graphics, and searchable layers are preserved sharply, while the compression engine focuses on the parts of the document that tend to create unnecessary size. That makes the tool useful for application portals, client handoffs, and internal document workflows where readability matters just as much as hitting a smaller file size.
If you are trying to meet a strict target such as 1MB or 500KB, treat those as practical goals rather than guaranteed outcomes for every source file. A clean text-first PDF can shrink dramatically, while a scan with dense full-page photos may need stronger simplification. The related landing pages for 1MB and 500KB limits can help set expectations when you are working against a hard upload cap.
How to use PDF Compressor
Upload your PDF document.
Our engine automatically identifies potential size savings.
Download your optimized, smaller PDF file.
Best Use Cases
- Official document submissions
- Emailing large reports
- Archiving digital records
Compression Tips & Starting Settings
- "PDFs with many images see the most dramatic reduction."
- "Our tool preserves text-searchability and OCR layers."
Supported Formats
All transformation engines are optimized for high-fidelity output.
Frequently Asked Questions
Will my PDF lose text quality?
No. We selectively compress images and non-critical data. All vector graphics and text layers remain sharp.
Related guides for this workflow
The tool handles the processing, but these guides explain the choices around it: format decisions, upload-limit tradeoffs, ecommerce prep, and when resizing or compression is the better first move.
PDF Upload Limits by Portal: 13 Real Systems and the File Size Targets That Actually Work
If a portal says your PDF is too large, the right fix depends on the system. This guide maps 13 real portals and platforms to their documented file size caps, shows what happens when you exceed them, and explains how to choose the right compression target for each category.
Why Scanned PDFs Get So Large: DPI Math, Color Overhead, OCR Layers, and What Phone Scanner Apps Are Doing to Your File
Scanned PDFs are large because they are image containers first and documents second. The pixels created at scan time, the choice between grayscale and color, the compression profile applied by the scanner app, and the optional OCR text layer all determine the final weight. This guide breaks those pieces apart with benchmark-style examples so you can tell whether the real problem is DPI, color, OCR, or the app that made the file.
How to compress a PDF under 10 MB to send by email
Most email-attachment rejections come down to a single number: 10 MB. This guide explains the actual size limits enforced by major email providers, why PDFs balloon in the first place, which compression method fits your situation, and what to do when one file is still too heavy to send.
Reduce File Size for Job Application Portals: ATS Limits, Parser Quirks, and Why Your Resume Can Fail Without an Error
A resume can fail long before a recruiter reads it. Some ATS platforms block oversized files at upload, some accept the file but fail parsing later, and some behave differently depending on how the employer configured the portal. This guide focuses on the real ATS mechanics behind those failures so you can choose the right file size, format, and fallback path before you hit Apply.