Comparison

Compress It! PDF Compressor vs Function Fitter

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

Head to head
About

Compress It! PDF Compressor

Easily reduce the file size of your PDF documents with a simple, secure, and privacy-focused tool. Compress PDFs in just three steps, directly on your device, and share them instantly. Enjoy fast and efficient document management without complex features.

Highlights
  • PDF compression in 3 easy steps
  • Selectable compression levels
  • Import PDFs from files or other apps
  • Fast and secure on-device processing
  • Share and print compressed PDFs
  • Privacy-oriented design
Features
Read full description

+ PDF Compression in 3 easy steps + 1. Open App 2. Select compression level 3. Select PDF by importing from your files or from other apps It does not get any easier than this! With Compress it!, you can compress your PDF documents in a matter of seconds, securely. Forget about over-complicated apps with nonsense features. Compress it! is the most secure and privacy oriented PDF compressor available. Compress it! Features: + Simplicity + There is no need for complicated PDF compressors. Our app allows anyone to use fast and easy. (Design also helps!) + Fast and secure + Every PDF compression is done right on your device. That means all PDF files are securely stored on your device and the compression is done in seconds (As it should be!) + Share and Print + Export and share all your PDF documents right from the app with a single tap. Send via iMessage, Open in other apps, Print, etc. Compress It! is free to use and you have 2 free daily compressions per day. If you choose to subscribe to Compress It! Pro to enjoy unlimited compressions, payment will be charged to your iTunes account, and your account will be charged for renewal 24 hours prior to the end of the current period. Auto-renewal may be turned off at any time by going to your settings in the iTunes Store after purchase. Prices may vary from country to country. Privacy policy: https://pdfcompressit.app/privacy Terms of use: https://pdfcompressit.app/terms

About

Function Fitter

Features
Read full description

Function curve fitting using custom function that you enter. Reads data values either from file or manual entry, and tries to fit your function to the data by adjusting 1 to 4 parameters for a least-squares best fit. For enjoyment only, NOT for serious data needs. This is minimalist by design with no ads, no in-app purchases, no bells and whistles, and no fancy moving graphics to distract you, just fun. Note: Entertainment value only, fun using different parameter starting values.

Screenshots

Compress It! PDF Compressor4 screens
Function Fitter4 screens

Verdict

The call

The clearest difference is in-app purchases: Function Fitter at none against Compress It! PDF Compressor's 3. Compress It! PDF Compressor's advantage is update cadence (fortnightly vs every 5 weeks). On price, ads, device support and iOS requirement 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. Compress It! PDF Compressor sells 3 in-app purchases, starting at $2.49 per month. Function Fitter asks for nothing beyond the download.

UpkeepUpdate frequency

Compress It! PDF Compressor ships an update fortnightly, Function Fitter every 5 weeks. The most recent releases landed on November 7, 2026 and October 30, 2026 respectively.

Scorecard2 real differences · 8 level
Compress It! PDF Compressor versus Function Fitter: the parameters behind the verdict, then further details
ParameterCompress It! PDF CompressorFunction Fitter
PriceFreeFree
Rating4.8 (469 ratings) — better—
Positive reviews77.3% of reviews—
Number of ratings469 — better—
Update frequencyFortnightly — betterEvery 5 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPadiPhone, iPad
Requires iOS18.017.0 — better
Further details — not scored
Size21 MB4 MB
Age rating4+4+
DeveloperDIGISET LLC29Apps LLC

Bugs and requests

Compress It! PDF Compressor

Reported bugs

10 issues
  • Crashes when compressing files above 200mb on iPad 9th gen
  • Does not work with files over 300mb
  • Images in documents become big and pixelated
  • Cannot find compressed files on the device
  • 'Choose file' button does not work
Show 5 more
  • No option to compress photos
  • App does not work at all
  • App is fake and not working
  • App does nothing useful
  • Would not load the file at all

Requested features

6 requests
  • Allow compression of files over 300mb
  • Improve handling of images in documents
  • Clarify decompressing to original size functionality
  • Fix 'Choose file' button
  • Enable compression of photos
Show 1 more
  • Improve stability for large files

Function Fitter

Not enough reviews yet to summarise bugs or requests.

In-app purchases

3 purchases

Compress It! PDF Compressor

Subscriptions2
  • Compress It! Pro Monthly$2.491 Month
  • Compress It! Yearly Subscription$12.991 Year
One-time1
  • Compress It! Pro Lifetime$24.99
None

Function Fitter

No in-app purchases

Questions

Is Compress It! PDF Compressor free?
Compress It! PDF Compressor is free to download, with in-app purchases available.
Is Function Fitter free?
Function Fitter is free to download, with no in-app purchases.
Do Compress It! PDF Compressor or Function Fitter have ads?
Neither Compress It! PDF Compressor nor Function Fitter shows ads.
Which is updated more often, Compress It! PDF Compressor or Function Fitter?
Compress It! PDF Compressor ships an update fortnightly, and Function Fitter every 5 weeks. Most recently, Compress It! PDF Compressor was updated on November 7, 2026 and Function Fitter on October 30, 2026.

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