Comparison

PDF Under vs PDF Compressor

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

Head to head
About

PDF Under

Features
Read full description

Your PDF is ready. Then the upload form says: file too large. Maybe it needs to be under 10 MB. Or 2 MB. Or even 500 KB. You don't want to learn compression settings, and you definitely don't want to keep guessing—compress, check the size, try again, compress again. You just need the PDF to fit. That's what PDF Under is built for. Tell it the MB or KB you need, and it works toward exactly that number. But making a PDF smaller is only half the problem. It still has to look like your PDF. Some compression methods shrink a file by turning every page into a picture—smaller, yes, but the text is no longer selectable, and the document never quite looks right again. PDF Under does it differently. Whenever possible, it keeps your text and vector content untouched, and compresses only the embedded images that were taking up the space in the first place. Smaller file. Same document. You choose the number. 500 KB, 1 MB, 2 MB, 5 MB, 10 MB, or a custom target of your own—no "low, medium, high" guessing games, just the size you were actually asked for. And before you save or share anything, you see the result first: the final size, the finished pages, exactly what you're about to send. Where does this happen? On your phone. Not on a server somewhere. Your PDF is never uploaded, which matters more than usual when the document you're shrinking is the one you'd rather not hand to a random compression website in the first place. No account. No sign-in. Just your file, compressed, still yours. Now, the honest part. Not every target is reachable. A fifty-page scanned document doesn't become 500 KB without something giving—that's just how file size and image quality work, and PDF Under won't pretend otherwise. When your target is more aggressive than the document can survive, it tells you plainly, shows you the smallest version that's still readable, and lets you decide from there. No silent damage. No surprises when you open the file later. This is the app for the moment a portal, a form, an inbox, or a government website hands you a number and expects you to hit it—job applications, school submissions, legal filings, an email that keeps bouncing back because the attachment is too big. Select the PDF, set the target, compress, check the result, send it. Five steps, and you're done. PDF Under is free to try—your first three compressions cost nothing. After that, a Weekly, Yearly, or Lifetime plan unlocks unlimited use, so you're never stuck mid-deadline wondering if today's the day you run out. Subscriptions renew automatically unless canceled at least 24 hours before the current period ends, and you can manage or cancel anytime in your Apple Account settings. Full pricing is shown in the app before you're asked to pay anything. Because when a website tells you your PDF is too large, you shouldn't have to become a compression expert just to send a document. You should just be able to get it under the limit. By downloading, you agree to the Standard Apple End User License Agreement: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

PDF Compressor

Features
Read full description

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.

Screenshots

PDF Under4 screens
PDF Compressor2 screens

Verdict

The call

The clearest difference is in-app purchases: PDF Compressor at none against PDF Under's 3. PDF Compressor also leads on update cadence (every 8 days vs every 3 weeks) and iOS requirement (15.0 vs 17.6). PDF Under's advantage is ads (none vs shown). On price and device support there is nothing between them.

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. PDF Under sells 3 in-app purchases, starting at $1.99 per 7 days. PDF Compressor asks for nothing beyond the download.

UpkeepUpdate frequency

PDF Under ships an update every 3 weeks, PDF Compressor every 8 days. The most recent releases landed on October 9, 2026 and October 1, 2026 respectively.

Scorecard4 real differences · 2 level
PDF Under versus PDF Compressor: the parameters behind the verdict, then further details
ParameterPDF UnderPDF Compressor
PriceFreeFree
Update frequencyEvery 3 weeksEvery 8 days — better
AdsNo — betterYes
In-app purchasesYesNo — better
DevicesiPhoneiPhone, iPod — better
Requires iOS17.615.0 — better
Further details — not scored
Size3 MB5 MB
Age rating4+4+
DeveloperEmre KABOGLUTAREQ ALHUSAINI

In-app purchases

3 purchases

PDF Under

Subscriptions2
  • PDF Under Weekly$1.997 Days
  • PDF Under Yearly$13.991 Year
One-time1
  • PDF Under Lifetime$19.99
None

PDF Compressor

No in-app purchases

Questions

Is PDF Under free?
PDF Under is free to download, with in-app purchases available.
Is PDF Compressor free?
PDF Compressor is free to download, with no in-app purchases.
Do PDF Under or PDF Compressor have ads?
PDF Compressor shows ads; PDF Under does not.
Which is updated more often, PDF Under or PDF Compressor?
PDF Under ships an update every 3 weeks, and PDF Compressor every 8 days. Most recently, PDF Under was updated on October 9, 2026 and PDF Compressor on October 1, 2026.

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