The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →You can often make a PDF smaller without noticeably affecting how it reads, but no single compression setting works for every file. First identify whether its size comes mainly from images, fonts, or other document data. Then choose a targeted method, save a separate copy, and check the result at the size it will actually be viewed or printed.
Choose a compression method based on what is in the PDF
Image-heavy PDFs, especially scans and documents with photographs, often offer the most opportunity for size reduction. Text-based PDFs may instead benefit from removing or recompressing document data. An optimizer may not reduce a file that is already compressed or whose contents its settings do not affect.
As an Amazon Associate I earn from qualifying purchases.
| Method | Best fit | Quality and size tradeoff | Ease and considerations |
|---|---|---|---|
| Adobe Acrobat’s guided compression | Readers who want a graphical workflow | Outcome depends on the available settings and document contents; image compression or resampling can affect clarity. | Follow the desktop or web workflow below. Interface and available features vary by version and platform. |
| Ghostscript with pdfwrite | Technical users who can adjust command-line settings | Can rewrite a PDF, but a smaller output is not guaranteed. Lossy image recompression can reduce quality, particularly for images already JPEG-compressed. | Requires command-line use and careful review of settings and output. |
| qpdf | Technical users seeking limited stream recompression or structural operations | May reduce some file data, but does not resample images; it is not primarily a size optimizer. | Command-line utility; results depend on the PDF and the operation used. |
For Acrobat’s documented workflows, see Adobe’s guide to compressing a PDF and its PDF optimization help for Windows and macOS. Ghostscript explains the limits of its PDF optimization process, and qpdf documents its command-line options.
Understand which settings can affect quality
Lossless compression
Lossless compression preserves the image data, though it may not make a large difference if the PDF is already efficiently compressed. Adobe identifies Flate as a lossless compression method in its PDF creation settings documentation.
#1 Best Overall
- PORTABLE SCANNER FOR USE ON-THE-GO — The fastest and lightest mobile single-sheet-fed compact document scanner in its class¹
- QUICK DOCUMENT SCANNING ― This Epson ultra-fast scanner scans a single page as quickly as 5.5 seconds²; Windows and Mac compatible
- VERSATILE PAPER HANDLING ― Portable scanner scans documents up to 8.5 x 72 in; Also easily digitizes receipts and ID cards to make accounting, bookkeeping, and organizing simpler
- INTUITIVE, HIGH-SPEED SOFTWARE — Epson ScanSmart Software³ is a smart tool allowing you to easily scan, review, and save; Stay organized easily with the help of this Epson scanner
- EASY SETUP — USB-powered connect to your computer for quick and simple scanning; No batteries or external power supply required to operate portable document scanner; Standard Connectivity: USB 2.0
JPEG recompression and downsampling
JPEG compression is lossy: it can reduce file size by discarding image information. Downsampling lowers image resolution, which may be acceptable for screen viewing but can make fine detail less clear or weaken print results. The right setting depends on the page content and intended use; there is no universally safe resolution or percentage reduction.
Be especially cautious with scans, small text embedded in images, fine lines, and photographs. Recompressing images that are already JPEG-compressed can degrade them further. Adobe describes compression levels intended to balance file size and image or graphic quality in its PDF Services compression documentation, but those levels do not guarantee a particular result for every PDF.
Rank #2
- FAST SPEEDS - Scans color and black and white documents a blazing speed up to 16ppm (1). Color scanning won’t slow you down as the color scan speed is the same as the black and white scan speed.
- ULTRA COMPACT – At less than 1 foot in length and only about 1. 5lbs in weight you can fit this device virtually anywhere (a bag, a purse, even a pocket).
- READY WHENEVER YOU ARE – The DS-640 mobile scanner is powered via an included micro USB 3. 0 cable allowing you to use it even where there is no outlet available. Plug it into you PC or laptop and you are ready to scan.
- WORKS YOUR WAY – Use the Brother free iPrint&Scan desktop app for scanning to multiple “Scan-to” destinations like PC, Network, cloud services, Email and OCR. (2) Supports Windows, Mac and Linux and TWAIN/WIA for PC/ICA for Mac/SANE drivers. (3)
- OPTIMIZE IMAGES AND TEXT – Automatic color detection/adjustment, image rotation (PC only), bleed through prevention/background removal, text enhancement, color drop to enhance scans. Software suite includes document management and OCR software. (4)
Compress a PDF in Adobe Acrobat
Adobe’s learning page, updated April 23, 2026, documents the following desktop and web routes. Labels and availability can vary with Acrobat version and platform.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →- Desktop: Open the PDF in Acrobat, choose the Compress a PDF tool, and save the compressed result as a separate file.
- Web: Sign in to Acrobat, choose Convert > Compress a PDF, select the file, and start compression.
- Reduced-size workflow: In Acrobat on Windows or macOS, choose Save as Other > Reduced size PDF, select compatibility, and save the output. Adobe’s help page documenting this workflow was last updated September 23, 2025.
Keep the original rather than overwriting it. If Acrobat offers multiple compression choices, begin with a less aggressive option when readability matters more than reaching the smallest possible file.
Rank #3
- STAY ORGANIZED – Easily convert your paper documents into digital formats like searchable PDF files, JPEGs, and more.Power Consumption : 2.5W or less (Energy Saving Mode: 0.7W). Suggested Daily Volume : 500 scans..Does it contain liquid: no
- CONVENIENT AND PORTABLE –lightweight and small in size, you can take the scanner anywhere from home offices, classrooms, remote offices, and anywhere in between
- HANDLES VARIOUS MEDIA TYPES – Digitize receipts, business cards, plastic or embossed cards, reports, legal documents, and more
- FAST AND EFFICIENT – No technical hurdles or complicated setups here; easily scan both sides of a document at the same time, in color or black-and-white, at up to 12 pages-per-minute, and with a 20 sheet automatic feeder
- BROAD COMPATIBILITY – Works with both Windows and Mac devices, be it laptop or computer
Use command-line tools when you need more control
Ghostscript
Ghostscript’s pdfwrite output device can rewrite PDFs, with settings that affect image size. Its documentation cautions that processing does not guarantee a smaller file. Lossy recompression can reduce quality, and recompressing already JPEG-compressed images can cause substantial degradation. Use it only when you are comfortable choosing settings and inspecting the output; it is not a reliable one-click solution for every document.
qpdf
qpdf supports some stream recompression and other operations that may help reduce file size. Its documentation says size optimization is not its primary purpose, and it does not resample images. It is therefore more relevant when the opportunity lies in document streams or structure than when oversized scans or photographs are the main problem.
Rank #4
- IRIScan Express, portable scanner : scans color and black and white documents a blazing speed up to 8ppm simplex. Color scanning won’t slow you down as the color scan speed is the same as the black and white scan speed.
- IRIScan Express mobile scanner is powered via an included micro USB 2. 0 cable allowing you to use it even where there is no outlet available. Plug it into you PC or laptop and you are ready to scan. USB cable provided. AC Adapter not provided and not needed.
- IRIScan flatbed scanner uses a simplex scanning mode allows for quick and straightforward scanning of single-sided documents. IRIScan with its full portable features is the ideal document scanners for computers.
- IRIScan document scanner : Versatile scanning capabilities, including scanning to Word, PDF, and Excel formats with companion software provided Readiris OCR
- Receipt scanner and card scanner with Additional features include scanning business cards directly to Outlook, photo scanning, and receipt scanning for efficient document management
Check the output before sending or replacing the original
- Note the original file size and make a copy to compress.
- Open the result and compare its file size with the original. If it barely changed, the file may already be optimized or the selected operation may not target its largest contents.
- Inspect small text, fine lines, photographs, and any pages where detail matters. Check them at the intended screen-viewing size and, if relevant, in a print preview or a test print.
- Confirm that the PDF’s pages and features you need still work before sharing it or replacing the source.
- If quality is poor, return to the original and try a less aggressive or more targeted setting rather than repeatedly compressing the already reduced copy.
For browser-based compression, the cited product workflows do not establish current account requirements, pricing, or data-retention terms. Check the service’s current terms before uploading a PDF containing sensitive information.
Quick Recap
Best Value
- Scanner type: Document
- Connectivity technology: USB
- With Auto Scan Mode, the scanner automatically detects what you're scanning
- Digitize documents and images
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
