ChopShop documentation

The everyday audio + video editor for Mac, iPhone and iPad. Open a clip, chop it, ship it. This page walks through every feature in the order you'd actually meet it: install, drop a clip, edit, export. It describes the Mac app; On iPhone and iPad covers what's different on a touchscreen.

Installation

ChopShop comes three ways on the Mac. The download from bendansby.com/apps/chopshop is a standard .dmg — open it and drag ChopShop.app to your Applications folder. The Mac App Store version installs and updates the usual way. The Setapp version installs through the Setapp client; no separate license key, no trial.

Requires macOS 15 Sequoia or later, on Apple Silicon or Intel. The direct-download build auto-updates via Sparkle; you can also check anytime via ChopShop → Check for Updates…. The Mac App Store and Setapp builds update through their own channels. See License for the differences between the three.

There's also a native iPhone and iPad app on the App Store. It's the same purchase as the Mac App Store version — buy it once and it's on all three. See On iPhone and iPad.

Supported formats

ChopShop opens any media file macOS reads natively — MP4, MOV, M4V, M4A, MP3, WAV, AIFF, AAC — plus four formats it converts on import:

• Matroska (.mkv)
• WebM (.webm)
• Ogg (.ogg, .ogv, .oga, .opus)
• FLAC (.flac)

The conversion runs in the background the first time you import a given file and is cached, so re-opening the same source is instant. MKV files that already contain H.264 or HEVC video and AAC audio are repacked without re-encoding — no quality loss, no wait. Everything else is re-encoded via Apple's hardware video and audio encoders, which means full speed on Apple Silicon.

Conversion is powered by a bundled LGPL build of FFmpeg. Corresponding source is at bendansby.com/apps/chopshop/ffmpeg-source/; the LGPL v3 notice is in the About ChopShop window.

Quick start

1. Open ChopShop. Either click Choose Files… or drag any media file from the Finder onto the window.
2. The video appears in the preview area at the top; the timeline shows the clip on its rails at the bottom — video on top, audio underneath.
3. Press Space to play, again to pause.
4. Move the playhead to where you want to cut and press ⌘K. The clip splits in two — drag the half you don't want off the timeline, or press ⌫ to delete it.
5. Press ⌘E to export. Pick a format, pick a location, done.

The .chop file

Your project saves as a .chop file. It's small — kilobytes — because it doesn't contain any of your media; it just remembers which files you imported, where they sit on the timeline, and how you trimmed them. You can move .chop files around, email them, keep them in any folder.

If you move one of the source clips out from under it, ChopShop will ask you to point to the new location the next time you open the project. See Missing media.

Layout

The window has two parts:

• Preview area at the top — your video plays here.
• Footer panel at the bottom — the play button, timecode, timeline, and Crop / Export buttons live here.

Hover the empty strip across the top of the window to see the document name; click it to drop a Finder-style path menu. Drag anywhere in the preview area to move the window around your screen.

View → Fit Window to Video (⌘⇧0) sizes the window so the video fills the preview area exactly — no black bars.

Audio + video tracks

The timeline has two rows: a video row on top (film-strip icon in the gutter on the left), an audio row underneath (waveform icon). A clip with both video and audio sits on both rows by default and moves as one.

Right-click a clip → Unlink Audio (or press ⌘⌥L) to separate the two halves so you can slide one without the other — useful for J and L cuts. Right-click again → Re-link Audio to reattach them.

Selecting clips

Click any clip to select it. ⇧-click extends the selection to a range; ⌘-click adds or removes single clips from the selection. You can mix-and-match across both rows in one selection.

Click an empty gap between clips to select the gap. With a gap selected, press ⌫ to collapse it — every later clip slides left to close the hole. The button in the footer flips between Delete Clip and Collapse Gap so you can tell what ⌫ will do.

Scrubbing and playback

Space plays and pauses. Drag the round playhead handle above the timeline to scrub by hand; playback pauses automatically while you drag.

The cyan LCD readout in the footer shows the current time and (for video projects) the current frame number.

The arrow keys move the playhead one frame at a time. Hold modifier keys to step farther or to slide the selected clip instead:

Trimming

Hover any clip — small chevrons appear at the left and right edges. Drag an edge to trim. While you drag, the preview shows the source video at the new in/out point so you can see exactly where you're landing.

Release to commit. ⌘Z undoes.

You can also mark in/out from the playhead. With a clip selected, position the playhead and press I for Set In, O for Set Out.

Splitting

⌘K (or Clip → Split at Playhead) splits the clip under the playhead in two. When more than one clip overlaps the playhead, the split prefers your selected clip; without a selection, it splits the topmost clip.

Deleting and collapsing

⌫ deletes the selected clip. If multiple clips are selected, they all go in a single undo step. If a gap is selected instead, ⌫ collapses the gap — every later clip on both rows slides left to close it. The audio and video halves of any unlinked pairs stay aligned with each other through the slide.

Link / Unlink audio

A video clip with sound starts linked — the audio and video halves move together. ⌘⌥L toggles the link state:

• Linked. Drag, trim, or split affects both halves in lockstep.
• Unlinked. The two halves move independently. Use this for J cuts (audio leads the video by a beat) and L cuts (audio trails into the next shot).

Unlinked halves still share a colour and a link badge — click the badge on either to reattach them.

Retime

Select one or more clips and pick Clip → Retime…. The sheet offers three presets — half speed (0.5×), normal (1×), and double speed (2×) — plus a slider for any rate in between. The footer of the sheet shows how the timeline length will change so you can see how much room a retime gains or loses.

One Apply covers the whole selection in a single undo step. A clip's audio and video stay in sync even if you'd previously unlinked them.

Reverse

Select clips and pick Clip → Reverse. Reversing video is heavy work, so ChopShop quietly renders a reversed copy in the background while you keep editing. A spinning indicator in the clip body lets you know it's working; you can still scrub the forward version in the meantime. When the render finishes, playback flips to reversed.

Reversed copies are kept on hand, so toggling reverse off and back on is instant. If you save and reopen the project later, the reversed copy re-renders in the background and the result is the same.

Export

Press ⌘E to open the export sheet:

• Format. MP4 or MOV for video projects; M4A or WAV for audio-only.
• Filename. Defaults to the first clip's name with - chopped appended.
• Width. Export at any width in pixels; the height follows automatically so the picture keeps its proportions, and Reset puts it back to the source's own size. Video projects only.
• Output. A short status line showing how many clips, the total duration, and whether the export will be lossless or re-encoded — see below.

Click Save…, pick a destination, and ChopShop runs the export. When it finishes, the Finder reveals the file. If something goes wrong, ChopShop tells you why instead of failing silently.

Switch to another app mid-export and ChopShop notifies you the moment it's done, so a long re-encode doesn't need watching. Click the notification to come back to the app. Nothing is posted while ChopShop is frontmost — you get the Finder reveal instead.

Crop on export

Click Crop… in the footer (or Edit → Crop…). Crop is set by output size: type the width and height in pixels you want the exported picture to be, then use the 3×3 origin grid to say where that frame sits inside the source — a corner, an edge, or the middle. Turn on Maintain proportions to keep the source's aspect ratio while you resize.

The preview keeps showing the uncropped frame, with a translucent red overlay marking what will be trimmed — so you can see exactly what the export will keep. The overlay skips stretches of the timeline that are audio-only, where there's nothing to crop.

Clips of different sizes are placed into the output canvas first and cropped after, so one crop frames every clip in the project the same way.

Lossless vs re-encode

The status line below the timeline tells you which kind of export is queued up:

• Lossless ✓ — every clip shares the same format, no crop is set, and no clips overlap. ChopShop can stitch them together without re-encoding, so the export finishes in seconds and the picture is identical to the source.
• Re-encode — at least one of those conditions doesn't hold. ChopShop re-encodes the output once and tells you the reason in parentheses (crop, overlap, mixed formats, watermark, etc).

Copy current frame

Right-click the preview area → Copy Current Frame, or pick Edit → Copy Current Frame. Captures the current frame to the clipboard as a PNG — without the red crop overlay. Disabled when the playhead is over an audio-only section.

Missing media

If you open a project whose source files have been moved or deleted, the missing clips appear on the timeline as hatched warning bars labeled Missing: filename.mov. Click Locate… on the bar (or right-click → Locate File…) to pick the file from a Finder dialog.

The relinked clip keeps its trim, timeline position, link state, and playback rate. If the new file happens to be shorter than the old trim, the trim shrinks to fit.

On iPhone and iPad

ChopShop is a native iPhone and iPad app as well — the same editor, adapted to the screen rather than cut down. The two-track timeline, trim handles, split, link/unlink, retime, reverse, crop and export all work the way they do on the Mac, and it reads and writes the same .chop file, so a cut you start in one place opens in the other.

• iPad keeps the Mac's proportions: preview on top, transport and timeline together in one footer.
• iPhone splits that transport across two rows in portrait, and tightens every measurement in landscape, where the whole screen is shorter than the iPad's footer alone. Same controls either way.
• Clip actions live behind the … button on the clip itself — Split at Playhead, Set In, Set Out, Re-link Audio, Reverse, Retime, Cut/Copy/Paste and Delete Clip. A missing clip shows Locate File… there instead.
• Import from Files or from your photo library. Export hands the finished file to the system save sheet, so it lands wherever you keep things.
• Projects open and save through the system document browser, so they can live in iCloud Drive or anywhere else.
• With a hardware keyboard attached, the common shortcuts work: Space, I, O, ⌘K, ⌫, ⌘I, ⌘E, ⌘Z.
• No export notifications here. If an export finishes while you're in another app, the save sheet is waiting the moment you come back.

The iPhone and iPad app is a single App Store purchase shared with the Mac App Store version. There's no trial, no license key, and no Setapp build on iOS.

Keyboard shortcuts Mac

The single-letter shortcuts (I, O, ⌫, arrow keys, Space) pause themselves whenever a text field has focus — so typing in the Crop, Retime, or Export dialogs always types letters, not commands.

Languages

ChopShop is localized into English, Deutsch, Español, Français, Italiano, 日本語, 한국어, Português (Brasil), Українська, Русский, and 简体中文. It picks the right language automatically based on your System Settings → General → Language & Region preferences.

To pin ChopShop to a specific language without changing system preferences, open System Settings → General → Language & Region → Applications, click the + button, and pick ChopShop.

License

ChopShop ships through three channels on the Mac — pick the one that fits how you like to pay for software:

• Direct download. 7-day free trial with every feature unlocked, no watermark, no reminders. A one-time license then unlocks unlimited clean exports. Buy via ChopShop → Buy License… in the menu bar; activate via Enter License…. Activation needs the internet briefly, then works offline; ChopShop revalidates quietly in the background so refunded or revoked keys stop working. Once the trial ends (and only until a license is entered):
  • Every other export shows a quick license reminder.
  • Video exports get a translucent "Cut with ChopShop" stamp across the centre of each frame.
  • Audio-only exports get a brief spoken "Cut with ChopShop" tag mixed in every twenty seconds.
• Mac App Store. Paid through Apple's standard pipeline — buy it once, no separate license key, no trial. The same purchase covers the iPhone and iPad app.
• Setapp. Included with a Setapp subscription. No separate license key; Setapp delivers updates automatically.