I was running ImageOptim for images, HandBrake for video, and a paid PDF tool for shrinking documents. That is three apps to install, three menus in my dock, and three different mental models for what “compress” means. Then I tried Dinky (a free Mac compression utility that handles images, videos, audio, and PDFs in one window) for a week and replaced all three. It does not have every feature of the apps it replaces, but for the 80% of compression I actually do, it is one drag-and-drop instead of three.
If you compress files on a Mac often enough to have a folder of one-off tools, Dinky is worth an afternoon.
What Dinky actually does
Dinky is a single Mac app that compresses images, videos, audio files, and PDFs locally. Nothing is uploaded anywhere. You drag a file in (or a folder, or a URL, or a clipboard image), pick a preset or a target format, and a smaller file comes out the other side. The original stays where it is unless you tell Dinky to move it.
The app treats each file type differently. Images can export to WebP, AVIF, HEIC, or lossless PNG. Videos export to MP4 with H.264 or HEVC and a quality slider. Audio can convert between AAC, MP3, FLAC, WAV, ALAC, and AIFF. PDFs can be flattened (which shrinks scanned or image-heavy documents) or rewritten (which keeps text and links searchable). The same window handles all four, which is the whole point.
The image case is the strongest
For images, Dinky has more controls than ImageOptim in a smaller interface. Smart Quality detects whether an image looks like a photo or a graphic and picks the right compression for each. You can also set a max width to downscale before compression, target a specific file size, or just output WebP at a chosen quality. The defaults are good. I have not opened ImageOptim in three weeks.
A few image presets I use:
- Blog photos. WebP at quality 80, max width 1600 px. Output averages 60-70% smaller than the original JPEG with no visible loss.
- Screenshots. PNG for lossless (smaller than the system screenshot PNG because of better compression settings). For sharing, convert to WebP at quality 90.
- Email attachments. JPEG at quality 75, max width 1200 px. Always under 1 MB.
- Social media posts. WebP at quality 85, max width 1200 px. Most platforms will re-compress on upload, so the goal here is a clean source file, not a small upload.
The Smart Quality switch covers the case where you do not know what you are compressing and just want it smaller. It works on photos. It works on screenshots. It works on scanned documents. It is the default for the people who do not want to think.
Video and audio are good enough
Dinky is not HandBrake. There is no per-codec bitrate calculator, no chapter marker editor, no subtitle track handling. For “I exported a screen recording and I want a smaller MP4,” it is plenty. You set the codec (H.264 or HEVC), pick a quality preset, optionally cap the frame rate, and wait. A 5-minute 1080p screen recording at 60 fps drops from about 800 MB to about 80 MB at H.264 quality 70. That is the case I actually need.
Audio conversion is more interesting than it sounds. I had a folder of WAVs from a recording session that needed to ship as FLAC for archival and as MP3 for sharing. Dinky handled both in one batch. The output file names were predictable, the metadata was preserved, and the process did not require opening a separate audio editor.
PDF handling is the surprise
PDFs are the type that most “compress” apps either ignore or destroy. Dinky gives you two paths. Flattening rebuilds the PDF without keeping text and link data, which is fine for scanned documents and image-heavy files where you only need the visual content. Rewriting keeps text and links intact and applies mild compression to the embedded images. For a 30 MB scanned PDF I had lying around, flattening produced a 4 MB version that looked identical. For a text-heavy PDF I needed to forward, rewriting produced an 18 MB version with searchable text and clickable links. Both were good outcomes.
The OCR option (a separate toggle that runs optical character recognition on flattened scans before saving, so the output is searchable even after flattening) is the feature I did not know I wanted. A scan of an old manual went from a 50 MB image-only PDF to a 6 MB searchable PDF in about 20 seconds. That is a real workflow improvement.
Workflow features that make it more than a one-off
Three small features turn Dinky from a tool you try once into a tool you keep using:
- Presets. Save a preset for blog images, another for client PDFs, a third for lightweight video exports. Each preset bundles the format, quality, size limits, destination folder, and filename pattern. Switching between workflows is one click instead of redoing the same five toggles.
- Watch folders. Drop files into a watched folder and Dinky compresses them automatically with your chosen preset. I have a folder on my desktop called “to-compress” that catches screenshots and screen recordings during the day. A cron-like cleanup pass runs at the end of every hour and the originals land in trash.
- Clipboard shortcut. Press Command + Shift + V from anywhere on the Mac and Dinky compresses the image on your clipboard. This is the feature that turned Dinky from “a tool I open when I need it” into “a tool that is always there.” It is genuinely useful for anyone who pastes screenshots into chat or tickets.
The batch processing controls (how many jobs run in parallel) are honest. The default is conservative. If you have 200 images to process, bumping parallel jobs to 4 cuts wall-clock time roughly in half on a recent Mac. The CPU monitor in the app tells you when you are saturating cores.
What I gave up
Dinky is not a full video editor. There is no HandBrake-equivalent for fine-grained codec control. If you encode video for production and you care about exact bitrates, you keep HandBrake.
PDF rewriting is also not Acrobat. If you need to reorder pages, add watermarks, or fill forms, you need a real PDF editor. Dinky handles “make this smaller and keep it readable,” which is what I needed, but it is not a replacement for serious PDF work.
Finally, Dinky is a paid app on the Mac App Store (about $8 last I checked) with a free trial. The article title says “free” because the trial is long enough to evaluate, and there is a free version that handles the common image cases. If you outgrow the free version, the upgrade is cheap.
Trade-offs
Dinky is a single-developer app, not a suite from a major vendor. Updates are infrequent. There is no enterprise support contract. If the developer stops maintaining it, you are back to running three apps. The trade is consolidation for vendor risk, which is a calculation you have to make.
Local-only processing means your files never leave the Mac. There is no cloud sync, no team sharing, no cross-device library. That is the upside for privacy and the downside for collaboration. If you want to share a compression preset across two Macs, you copy the preset file manually.
If you do most of your compression on a single Mac and you want fewer apps in your dock, Dinky is a clear win. If you work across multiple machines and need a shared preset library, the consolidation is not worth it.
Bottom line
Dinky replaced three apps on my Mac with one. Image handling is the strongest feature. Video and audio are good enough for what I actually do. PDF flattening with OCR is a feature I did not expect to use and now use weekly. The clipboard shortcut is the single biggest workflow improvement. The $8 upgrade is cheap.
If you only do one thing from this article, install Dinky, set up one preset for the file type you compress most often, and try it for a week. If you find yourself reaching for it more than your old tool, you have your answer. The rest can wait.