Publishing content in Portable Document Format (PDF) brings countless advantages like formatting preservation, platform independence, content protection and more. However, PDF files also tend to carry lots of bloat in the form of high resolution images, embedded fonts, decorative elements and other space-hogging culprits.
Left unchecked, PDF bloat can produce needlessly massive files that frustrate readers and users alike. According to software testing company Capterra, the average PDF document today measures 70.4MB. But for online applications, the ideal target size is less than 1MB.
So what’s a well-meaning publisher to do? Never fear – with the right PDF compression tricks, you can dramatically slim down files to maximize shareability. This comprehensive guide explores seven surefire strategies to shrink PDFs while retaining quality and core content.
Average PDF File Sizes in 2022
Let’s kick things off by establishing some industry benchmarks around usual PDF dimensions. According to recent research published on Capterra:
- Average PDF file size = 70.4MB
- Median PDF file size = 9.6MB
- Over 25% of PDFs exceed 100MB
For downloading and sharing PDFs digitally, file sizes in the single or double digits of megabytes are ideal. Once you get above 10MB, readers on slower connections experience much longer load times.
Capterra’s research also revealed that:
- 15% of PDF users said file sizes over 25MB caused major access problems
- 47% reported some trouble downloading over 25MB
- 74% noted speed issues and lag trying to view PDFs over 25MB
So to recap – small PDFs good, big PDFs bad! Our mission is to transform those obese 50, 100 or even 500MB beastly documents into svelte little files users will delight in downloading.
1. Use “Save As” to Avoid Cumulative Bloat
The first tip in our PDF diet plan tackles an easy-to-overlook cause of size inflation over a document’s lifetime.
You see, the standard “Save” function in most PDF editing apps simply piles on incremental changes without optimizing. So each save operation increases filesize needlessly by appending revisions instead of rewriting entire document.
By contrast, “Save As” creates a fresh new file on every save, forcing the app to compress and optimize from scratch. This keeps bloat from accumulating addition after addition.
Action Step: Adopt two key habits to avoid runaway PDF bloat:
- Use “Save As” frequently while editing: Give each file variation a unique name reflecting its date or development stage. Example:
My PDF Design - v1_January 28, 2023 - When finished, keep only the smallest optimized “Save As” version: Discard interim draft files or move them to an archive folder. Working with the cleanest slate PDF eliminates unnecessary historical baggage.
Easy trick but over time it really keeps file bloat at bay!
2. Export as Reduced Size PDF
All advanced PDF editing suites like Adobe Acrobat, Foxit PhantomPDF, Nitro Pro and many others include proprietary exporting algorithms specifically designed to shrink file size.
For example in Adobe Acrobat:
- Open your overstuffed PDF
- Select File > Save As Other > Reduced Size PDF
- Additional options will appear allowing you to choose various optimization levels balancing compression intensity against potential quality loss
- Select your preferred settings then export a fresh compressed copy of the PDF
- Compare new PDF against original and adjust settings if further reduction needed
This leverages Adobe’s specially developed compression codecs to corral wild PDF obesity. Similar one-click export options in platforms like Foxit and Nitro employ the same concept with varying degrees of custom controls available.
3. Deploy a Dedicated Online PDF Compressor
Don‘t want to buy or install desktop software just to slim down PDFs? Consider using one of the many free cloud-based tools available instead:
| Compressor | File Qty | Max Size | Key Features |
|---|---|---|---|
| Smallpdf | Multiple | 100MB each | Bulk compression plus editing tools |
| ILovePDF | Multiple | 200MB each | Intuitive drag and drop interface |
| PDF2Go | 1 | 10MB | No account required |
| PDFCompressor | 20 | 2GB each | Batch process for large volumes |
The online route means you can trim file fat quickly without taxing local storage space or CPU. Above are some of the most versatile free options accepting multiple large PDFs.
Just be aware that free tiers on these sites cap how many/how large the files you can compress per month. If you find yourself exceeding limits, investing in a premium account or standalone desktop software may become necessary.
4. Pinpoint Problem Areas with Audit Tools
First rule of optimizing PDFs: you can‘t fix what you can‘t find!
That‘s why advanced PDF editors like Adobe Acrobat Pro include auditing tools to map exactly which elements consume excess space.
For example in Acrobat, navigating to Tools > Analyze > Audit Space Usage scans an uploaded document and displays storage breakdowns like so:
Now you can see that images devour 60%+ of overall document size. Armed with specifics, you can configure advanced settings to aggressively shrink images while going easier on less bloated fonts, text, etc.
Foxit, Nitro and other premium PDF platforms provide similar analytics. If you don‘t have them, an affordable one-off purchasesolely for occasional optimization may still pay dividends long term.
5. Tweak Advanced Optimization Settings
Once you pinpoint exactly what‘s pumping up your PDFs, most paid editors include advanced controls for surgical file size slashing:
Aggressive Image Compression
Images consistently take the biggest bite out of overall document size. Enable advanced graphics setting like:
- Downsample or compress images above certain pixel dimensions. Reduce unnecessary megapixel bloat by targeting very large images.
- Set custom quality/compression levels per image object. Fine tune each image individually to balance quality against smaller footprint.
- Discard high resolution print images if you only require web/screen rendering.
- Convert certain RGB/CMYK images to grayscale to cut chroma channel overhead
Remove Redundant Font Glyphs
Fonts only used a handful of times still embed their entire glyph library – that‘s thousands of characters! So advanced options to cut the fat include:
- Substitute common fonts with system defaults. No need to bundle bold/italic variants users already have.
- Embed font subsets with only used glyphs. Inflates with more text but trims fonts rarely utilized.
- Restrict subset glyph count further for occasional decorative fonts.
Eliminate Non-essential Elements
Any decorative resources not vital to core content represent prime optimizer fodder:
- Alternate images like high-res prints harbored internally
- Unused interactive form elements and digital signature spaces
- Hidden layer content not intended for user visibility
- Custom document properties metadata rarely viewed but stored
Not every PDF needs be stripped down to skeletal essence – but removing truly non-critical elements prevents pointless bloat.
6. Standardize External Multimedia
One hugely ballooning factor comes from documents stuffing raw video, audio and interactive animations directly within. These resource-intensive assets bloat files tremendously even when only supplementing main content.
Instead, universally adopt external hosting for multimedia via cloud services:
- YouTube/Vimeo for video embedding
- SoundCloud for audio players
- GIPHY/Cloudinary for animated GIFs
Then simply insert links where relevant instead of injecting heavy binaries inside PDFs themselves.
You preserve full multimedia enrichments without the downsides of 1GB+ single file behemoths sluggish to share and navigate. Plus users enjoy responsive media loading separately on demand rather than one towering download.
7. Shrink Images Before Insertion
Finally, aggressively preprocess images for optimal compression before placing into editing software.
For example:
Resize Images Closer to Display Scale
Squash megapixels down to appropriate print dimensions where possible:
Those unnecessary pixels significantly raise file overhead.
Adjust Save Settings For Web
When saving processed images, leverage editor options ideal for digital delivery over print:
- Save using JPEG format at Quality level 7-9
- Set JPEG quality between 80-90% for best compression/quality tradeoff
- Enable progressive JPEGs to load faster online
Run Images Through External Compressor
Use specialized tools like TinyPNG to exponentially shrink images beyond editor capabilities:
The right preprocessor pairing works magic compared to PDF editor alone!
As you can see, images warrant extensive front-end pampering since they participate so actively in PDF bloating.
Bonus Topic: When PDF Just Won‘t Suffice…
Despite our most valiant attempts, certain documents still demand unreasonable disk real estate even in “optimized” PDF condition.
In these worst-case scenarios, it may be best to:
A) Revisit if PDF absolutely necessary
Other formats may suit certain use cases better:
- HTML for content heavy webpages
- EPUB for ebook distribution
- MP4 for interactive video
- GIF/SVG for standalone vector animations
B) Split PDF into manageable chunks
Don‘t force a single 500 page monster – break into logical segments:
- Chapters as separate documents
- Sections by related topics or asset types
- Prefer many PDFs under 25MB than one impractical 500MB file
We may need to relinquish PDF purity for pragmatic performance when sharing robust resources with the world.
When saving content in PDF form, it‘s dangerously easy to overlook hidden bloat cramming files to the gullet. But readers ultimately pay the price enduring glacial download waits imposed by our negligence.
Hopefully this guide illuminated several straightforward paths to responsibly slimming PDFs before unleashing upon innocent victims. Together we can build a world with lighter, nimbler PDFs that delight users rather than deter them!
Just remember…
- The average PDF today exceeds 70MB
- Over 25% of PDFs clock more than 100MB
- Target under 25MB for smoothest online performance
- Leverage 7 proven techniques to responsibly reduce PDF bloat
Now you have both compassionate motivation and actionable methods for producing gracefully optimized PDFs that users will graciously embrace rather than reluctantly suffer through! Go in peace sharing better PDFs.
