01
Prompt the way you think
Text, include-boxes, exclude-boxes — and combinations. SAM understands "person," "label," "dog." Shift-click to draw an and-not region.
New · macOS 26+ · Apple Silicon
Segment anything.
On your Mac.
Contour turns Meta's SAM 3 and SAM 3.1 into a real macOS workstation — drop in a folder or a video, write a prompt, get clean masks, boxes, tracked frames, and dataset-ready exports. Nothing uploads.
Apple Silicon 450 MB to 3.5 GB per model Pro · $19.99
Core framework
MLX + Metal
SAM variants
Six engines
Images + video
Unlimited batch
Data leaves Mac
Never
Screenshots
A real workstation — not a demo.
Drop in a folder, pick a model, prompt, run. Below: the editor, the model manager, batch processing, and the one-time Pro unlock.
Features
An instrument, not a magic wand.
Every feature is there because someone who segments for a living needed it. No confetti, no auto-enhance, no one-click magic.
02
Instant threshold tuning
Raw output is cached per image. Drag confidence, NMS, alpha, and minimum area — results re-render in hundreds of milliseconds, no re-inference.
03
Batch a whole collection
Point at a folder, set a prompt and model once, run. Status is tracked in SwiftData. Completed images skip on re-runs; crashes recover cleanly.
04
Track a whole video
Prompt once and follow objects through the clip — three modes, from 16 stable identities to 200 objects re-detected every frame. Scrub it back with a confidence timeline that flags where the track drifted.
05
Three overlay modes
Pixel mask, axis-aligned bbox, or oriented bbox — switch per export.
06
On device, via MLX
MLX for compute, Metal for GPU, Accelerate for SIMD mask composition. No cloud, no API key, no telemetry.
07
Real export formats
COCO JSON (with optional RLE), YOLO TXT bbox or polygon, mask PNG, cutout PNG. Video runs add a numbered mask sequence and ProRes 4444 carrying the mask as alpha.
Models
Pick the precision that fits the box.
SAM 3 and SAM 3.1 ship in several precisions — the six most useful shown here. Downloaded once from Hugging Face, color-coded in the toolbar so you always know what's loaded.
SAM 3.1 full
- Size
- ~3.5 GB
- Mem
- 16 GB+
- Precision
- F32
Latest architecture. Full precision. Drives video tracking.
SAM 3 full
- Size
- ~1.7 GB
- Mem
- 8 GB+
- Precision
- F32
Reliable baseline. Fast on most Apple Silicon.
SAM 3 · int8 quant
- Size
- ~900 MB
- Mem
- 8 GB+
- Precision
- INT8
Quantized · near-lossless for most prompts.
SAM 3 · int4 quant
- Size
- ~450 MB
- Mem
- 8 GB+
- Precision
- INT4
Smallest download. Trade accuracy for size.
SAM 3 · mxfp8 μfp
- Size
- ~900 MB
- Mem
- 8 GB+
- Precision
- MXFP8
Microscaling FP8 — finer scaling than INT8.
SAM 3 · mxfp4 μfp
- Size
- ~500 MB
- Mem
- 8 GB+
- Precision
- MXFP4
Microscaling FP4. Smallest modern-FP variant.
Workflow
Five steps, from folder to dataset.
No modal popups. No "AI magic." Each step is a tool in the workstation — toolbar-driven, menu-driven, keyboard-driven.
- 01
Collect
Drag in a folder of images, or a video file. SwiftData tracks status per image and per clip.
- 02
Pick a model
SAM 3 or 3.1, full-precision or quantized. Color-coded in the toolbar.
- 03
Prompt
Type a label, draw include / exclude boxes, or combine.
- 04
Tune
Sliders re-render from cache — no re-inference. Video runs get a scrubber and a confidence timeline instead.
- 05
Export
Mask PNG, cutout PNG, COCO JSON, YOLO TXT — plus a mask sequence and ProRes 4444 alpha for video.
Exports
Real formats. Nothing to reshape.
What comes out of Contour drops straight into your training pipeline — no round-tripping, no script-to-reshape, no CSV middleware.
COCO · annotations.json
COCO-format instance annotations with optional RLE-encoded masks.
{
"images": [...],
"annotations": [
{
"id": 1,
"image_id": 412,
"category_id": 1,
"bbox": [142,288,72,312],
"area": 18472,
"segmentation": {
"counts": "PYm03L4M...",
"size": [1920,1080]
},
"score": 0.97
}
]
} YOLO · IMG_0412.txt
YOLO txt — bbox or polygon format. Douglas-Peucker simplified.
0 0.186 0.554 0.038 0.520
0 0.452 0.554 0.038 0.520
0 0.742 0.576 0.037 0.510
0 0.867 0.598 0.036 0.498
0 0.092 0.620 0.024 0.391
# class_id cx cy w h
# normalized 0..1
# 5 detections MASK · IMG_0412_mask.png
Per-instance binary alpha masks. One PNG per detection.
IMG_0412/
├─ mask_001.png · 62 KB
├─ mask_002.png · 58 KB
├─ mask_003.png · 61 KB
├─ mask_004.png · 47 KB
└─ mask_005.png · 34 KB
5 masks · 262 KB total
1920×1080 · 8-bit alpha CUTOUT · IMG_0412_cut.png
Transparent-background cutouts — ready for compositing and matting.
IMG_0412/
├─ cutout_001.png · 240 KB
├─ cutout_002.png · 221 KB
├─ cutout_003.png · 204 KB
├─ cutout_004.png · 178 KB
└─ cutout_005.png · 132 KB
5 cutouts · RGBA
alpha channel preserved On device
Your client's unreleased imagery never leaves the machine.
Every model runs locally via MLX — Apple's machine learning framework for Apple Silicon — with Metal for GPU compute and Accelerate for SIMD-accelerated mask composition.
- No cloud inference. MLX runs on your GPU, not someone else's.
- No API key. No quota. No sign-in to segment.
- No telemetry. Contour makes zero outbound requests once models are cached.
- Model weights downloaded once from Hugging Face. Silent thereafter.
- Collections, masks, and caches stored in the app's SwiftData container — yours.
- Sandboxed. App-Store-ready. Notarized and hardened runtime.
Pricing
Free to try. One-time for Pro.
No subscription. Buy Pro once, own it. Free tier covers personal projects and exploration — Pro unlocks batch, video, and dataset exports.
Free
$0 forever
Personal use. One image at a time.
- All models · SAM 3, SAM 3.1, Florence 2
- Text + box prompts
- Slider tuning with live re-render
- Mask PNG + cutout PNG export
- Single-image segmentation
Pro
EARLY LAUNCH $19.99 $44.99 pay once · yours
Early launch price, down from $44.99
Everything. For people who segment for a living.
- Batch processing across collections
- Video segmentation · three tracking modes
- Frame-by-frame review with confidence timeline
- COCO JSON (with RLE) + YOLO TXT export
- Mask sequence + ProRes 4444 mask-as-alpha
- OBB · oriented bounding box output
- Shortcuts automation via App Intents
- All future 1.x updates
FAQ
Questions we actually get.
Missing one? Head to support , open an issue , or email support@mgcrea.io .
Q01 Does Contour need an internet connection?
Only once — to download model weights from Hugging Face on first use. After models are cached locally, Contour runs entirely offline. The app makes zero outbound requests during segmentation.
Q02 Which Macs can run it?
macOS 26 (Tahoe) or later on Apple Silicon. 8 GB of unified memory for quantized SAM 3; 16 GB+ recommended for full-precision SAM 3.1. Intel Macs are not supported — MLX and Metal require Apple Silicon.
Q03 How is this different from a one-click background remover?
A background remover is about the outline — one subject, one clean cutout. Contour is about the partition — many instances, each one identified, each one bounded, exportable as a dataset. Different problem, different tool.
Q04 Can I script it or automate batches?
Yes — through Apple Shortcuts. Contour ships App Intents for Process Folder, Process Video, Export Collection, and Reveal Latest Export, so you can chain segmentation into Shortcuts workflows, run them from Spotlight, or trigger them from the terminal with the built-in `shortcuts run` command. Batch-oriented intents require Pro. There is no separate CLI, AppleScript dictionary, or URL scheme.
Q05 Do I need to accept Meta's SAM license?
Yes. Contour gates SAM downloads behind a one-time license-acceptance prompt. After you accept, subsequent model pulls are silent.
Q06 What about my training data — is anything collected?
Nothing. Contour ships with no analytics, no crash reporter, no "help improve the product" telemetry. Images, masks, and caches live in the app's sandboxed SwiftData container on your machine.
Q07 Will there be a Linux or Windows version?
No. MLX is Apple-Silicon-only, and the app is built around macOS idioms — SwiftUI, SwiftData, Quick Look, Finder integration. A web or Linux port would be a different product.
Also from Magenta Creations 
Silhouette — Clean cutouts, in bulk.
Shipping product photos rather than training data? Silhouette does batch background removal with marketplace presets, edge control, and readiness checks.