The best PDF compressor for Mac
By Himanshu Ranjan · Updated 8 November 2026
For most people the best PDF compressor on a Mac is a desktop app that works offline. PDF Squeezer ($19.99) is a dedicated compressor with batch support. FileDial adds target-size presets like Email-safe (under 20 MB) inside a wider toolkit. Preview is free but has one fixed filter. Adobe's online compressor is free but uploads the file.
How we chose: FileDial is our product, so read this list with that in mind. We chose picks for PDF compression from each vendor's own published information (product pages, pricing pages, support docs and privacy statements), checked on 2026-11-09, plus FileDial's own documented behavior. We did not lab-test every tool or run size or speed benchmarks on the others, so we quote no numbers for them. Order reflects fit for this search, not who made the app. Checked 2026-11-09.
1. PDF Squeezer
PDF Squeezer does one job: making PDFs smaller, and it can strip unused fonts, metadata and annotations along the way. Witt Software says everything is processed on your device with no internet connection required, and it can batch compress files or whole folders including subfolders. It runs on macOS 11 or later, with separate iPhone, iPad and Windows versions.
- Processes files on your device, per the developer
- Batch compresses folders and subfolders
- Also on iPhone, iPad and Windows
- Focused on compression, so you need other apps for other PDF tasks
- Separate purchase per platform
2. FileDial
FileDial is our app. Its Compress category has Compress › Compress PDF (light), Compress PDF and Compress PDF (strong), which set images to 200, 144 or 96 dpi while text stays selectable, plus size targets such as Compress › Email-safe (under 20 MB), Gmail-safe (under 25 MB) and Compress to size…, which split the file into parts if it cannot get there. A 42 MB PDF compressed in about 2 seconds on a MacBook.
- Target-size presets for email and Gmail limits
- Saves a new file beside the original, with Undo
- Runs on the Mac with Wi-Fi off, one of 525 tools
- Not free after the 1-day trial
- Needs macOS 14 or later on an Apple silicon Mac (M1 or newer)
- Mac only, no iPhone or Windows version
3. Preview (built into macOS)
Open the PDF, choose File > Export and pick Reduce File Size from the Quartz Filter menu. Apple also offers export options such as Optimize images for screen and Save images as JPEG, and notes the result may be lower quality than the original. There is no size target and no batch mode.
- Already on every Mac
- Works offline
- Simple export step
- One filter with no strength control
- Apple warns quality can drop
- One file at a time
4. Adobe Acrobat online compressor
Adobe's web tool offers high, medium and low compression and handles files up to 2 GB. Adobe says your file is handled by Adobe servers and deleted unless you sign in to save it. It is a reasonable choice for non-sensitive files on a machine where you cannot install software.
- Works in any browser on any platform
- Three compression levels
- Files up to 2 GB
- Uploads the file to Adobe's servers
- Limited free use
- Saving requires an Adobe account
How we ranked these PDF compressors
Searchers looking for a PDF compressor usually have one concrete problem: a file is too big for an email attachment, a portal upload or a shared drive. So we ranked on three things: whether the tool works on the Mac without uploading the file, how much control it gives you over the result, and whether it handles several files at once.
PDF Squeezer comes first because it is a purpose-built compressor that processes files on the device and batch compresses whole folders, at a modest one-time price. FileDial is close behind and is the better fit if you also want size targets like Email-safe (under 20 MB) or you need other PDF tools such as merge, OCR or redaction in the same app. Preview is the free fallback, and Adobe's online tool is there for when you are not on your own Mac.
Why uploading a PDF to shrink it carries risk
Online compressors work, but the file leaves your computer. In March 2025 the FBI's Denver field office warned that free online document converters are increasingly used to spread malware, and that such sites can scrape personal data. In 2024 Cybernews reported that two online PDF services left storage open, exposing 89,062 user-uploaded files, including passports and contracts.
Reputable services such as Adobe state that they delete files, and for a restaurant menu that may be fine. For tax returns, contracts or medical letters, a desktop compressor removes the question entirely.
Picking a compression level without ruining the document
Most PDF compression works by downsampling and re-encoding the images inside the file. Text and vector drawings are already small, which is why a text-only PDF barely shrinks while a scanned or photo-heavy one can drop a lot. Lower image resolution means a smaller file but softer pictures, so start gentle and go stronger only if you still miss your limit.
In FileDial, Compress PDF (light) keeps images at 200 dpi, the standard option at 144 dpi and the strong option at 96 dpi, with text selectable in all three. If you just need to get under a fixed limit, the size-target tools step down automatically and split the file into parts if they cannot reach it, which avoids a guessing game.
When Preview is all you need
If you compress a PDF once in a while and the result only needs to look fine on screen, Preview's Reduce File Size filter is free and already installed. Check the exported copy before you send it, because Apple notes the output may be lower quality than the original, and keep the original in case you need to try again with different options.
Questions
Can I compress a PDF on a Mac for free?
Yes. Open the file in Preview, choose File > Export, pick Reduce File Size in the Quartz Filter menu and save. It is free and offline but gives you one fixed filter with no size target, and Apple notes the result may be lower quality than the original. For more control or batches, a dedicated app is easier.
Does compressing a PDF make the text blurry?
It should not. Good compressors re-encode the images inside the PDF and leave text and vector graphics alone, so text stays sharp and selectable. FileDial's Compress PDF tools state that text stays selectable at every level. Pictures and scanned pages are what lose detail as you compress more strongly.
Which PDF compressor works without uploading files?
PDF Squeezer, FileDial and Preview all run on the Mac. Witt Software says PDF Squeezer processes everything on your device without an internet connection, and every FileDial tool works with Wi-Fi off. Adobe's online compressor sends the file to Adobe's servers.