Comparison

PDF Compressor vs UnderLimit

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

PDF Compressor

Features
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Compress PDF files quickly, reduce file size, and keep your documents private with PDF Compressor: Reduce PDF. Need to make a PDF smaller for email, work, school, online forms, or document uploads? PDF Compressor helps you reduce PDF file size directly on your iPhone or iPad — with no account required and no document uploads to our servers. SMART PDF COMPRESSION Reduce PDF size while preserving text, links, and document structure whenever possible. Smart Compression is ideal for documents where readability and selectable text matter. MULTIPLE COMPRESSION OPTIONS Choose the compression method that fits your needs: • Smart Compression — Reduce file size while preserving text and links • Maximum Compression — Get a smaller file using stronger compression • Target Size — Try to compress your PDF toward 500 KB, 1 MB, 2 MB, 5 MB, or a custom size • Multiple quality options for stronger compression BUILT FOR REAL-WORLD FILE SIZE LIMITS Trying to upload a PDF but the file is too large? Choose a target size and let PDF Compressor reduce the document as much as possible while protecting its structure. Some PDFs are already highly optimized, so the exact target size cannot always be reached. The app clearly tells you when further compression would reduce document quality or make the file larger. PRIVATE — YOUR PDFs STAY ON YOUR DEVICE Your PDF documents are processed locally on your device. • No PDF uploads to our servers • No account required • No sign-in required • Your original PDF is never overwritten • Save or share the compressed copy only when you choose PREVIEW BEFORE AND AFTER Preview your PDF before compression and check the compressed version when processing is complete. CLEAR COMPRESSION RESULTS See exactly what happened to your document: • Original file size • Compressed file size • Percentage of space saved • Compression method used • Whether text and links were preserved SAVE AND SHARE EASILY Save your compressed PDF to Files or share it directly using the standard iOS sharing options. PDF Compressor: Reduce PDF is designed to make reducing PDF file sizes simple, fast, and private. Choose a PDF, select your compression method, reduce its size, and save the result.

About

UnderLimit

Features
Read full description

Make your files fit the limit. UnderLimit helps you reduce photos and PDFs to the file size you actually need. Choose your target size, and UnderLimit handles the compression while preserving the best quality possible. PERFECT FOR FILE SIZE LIMITS Need a photo under 1 MB? A PDF under 5 MB? An attachment small enough to upload or send? Set the target size and let UnderLimit do the work. PHOTO COMPRESSION • Compress photos to a target file size • Reduce image size in KB or MB • Keep the best quality possible • Quickly prepare images for uploads, forms, email, and sharing PDF COMPRESSION • Reduce PDF file size • Choose the maximum size you need • Prepare PDFs for upload limits and attachments • Simple, fast workflow SMART RECOMMENDATIONS Not sure which target size to choose? UnderLimit can help you select an appropriate size for your file. PRIVATE BY DESIGN Your files are processed directly on your device. Your photos and PDFs don't need to be uploaded to a remote server for compression. SIMPLE PRICING Start using UnderLimit for free. If you need more, unlock UnderLimit Unlimited with a one-time purchase. No subscription. No ads. No account required. UNDERLIMIT IS USEFUL FOR • Online forms and portals • Email attachments • Applications and document submissions • Websites with maximum upload sizes • Reducing photos before sharing • Compressing PDFs for size-restricted uploads Stop guessing compression levels. Choose the size you need and make your file fit the limit.

Screenshots

PDF Compressor2 screens
UnderLimit4 screens

Verdict

The call

The clearest difference is in-app purchases: PDF Compressor at none against UnderLimit's 1. PDF Compressor also leads on iOS requirement (15.0 vs 17.0). UnderLimit's advantage is ads (none vs shown) and update cadence (every 2 days vs every 8 days). On price and device support there is nothing between them.

Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. UnderLimit sells 1 one-off in-app purchase. PDF Compressor asks for nothing beyond the download.

UpkeepUpdate frequency

PDF Compressor ships an update every 8 days, UnderLimit every 2 days. The most recent releases landed on October 1, 2026 and October 14, 2026 respectively.

Scorecard4 real differences Ā· 2 level
PDF Compressor versus UnderLimit: the parameters behind the verdict, then further details
ParameterPDF CompressorUnderLimit
PriceFreeFree
Update frequencyEvery 8 daysEvery 2 days — better
AdsYesNo — better
In-app purchasesNo — betterYes
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size5 MB4 MB
Age rating4+4+
DeveloperTAREQ ALHUSAINIALESSANDRO VINCENZO DEL BALZO

In-app purchases

None

PDF Compressor

No in-app purchases

1 purchases

UnderLimit

One-time1
  • UnderLimit Unlimited$2.99

Questions

Is PDF Compressor free?
PDF Compressor is free to download, with no in-app purchases.
Is UnderLimit free?
UnderLimit is free to download, with in-app purchases available.
Do PDF Compressor or UnderLimit have ads?
PDF Compressor shows ads; UnderLimit does not.
Which is updated more often, PDF Compressor or UnderLimit?
PDF Compressor ships an update every 8 days, and UnderLimit every 2 days. Most recently, PDF Compressor was updated on October 1, 2026 and UnderLimit on October 14, 2026.

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