One window. The whole job.
Track list, subtitle table, video, waveform and editor, arranged the way you work. Collapse panels, resize the waveform, detach the video to a second screen.
Waveform & spectrogram
Spot to a scrollable waveform and an RX-style spectrogram. Voice-activity detection finds the dialogue for you.
Frame-accurate editing
SMPTE and drop-frame timecodes, live CPS / CPL / WPM thresholds, partial italics, vertical and horizontal positioning.
Live video preview
Subtitles over the video exactly as they will render, with JKL shuttle control. Plays a DCP's picture too.
Multi-track projects
Compare subtitle files side by side, convert between formats, merge translations, manage a multi-language release.
Quality control
Per-format conformance checks before export, a native grammar and spelling linter, shot-change detection, resync to the video.
Native, light, fast
Written in Swift. No Electron, no browser engine. Instant launch, 4K playback and waveforms on Apple Silicon and Intel.
Every format a deliverable can ask for.
Everyday and interchange formats are free. Broadcast and cinema delivery is unlocked with Pro.
Free · import & export11 formats
- SRTSubRip, the universal one
- WebVTTHTML5 text tracksW3C
- TTMLTimed Text MarkupW3C
- DaVinci TTMLtuned for Resolve
- ASS / SSAstyled subtitles
- FCP XMLFinal Cut Profcpxml
- Premiere XMLCC round-tripxmeml
- AvidDS / MC caption text.txt
- TXT · DOCX · XLSXreview & hand-off
- DCP SMPTEdigital cinemaST 428-7
- DCP InterOpdigital cinemaCineCanvas
Pro · broadcast & cinema delivery5 formats
- EBU STLbroadcast subtitlesTech 3264
- SCCclosed captionsCEA-608 / 708
- Netflix TTMLNetflix-conformantIMSC 1
- Amazon DFXPPrime VideoDFXP
- iTunes TTMLApple iTunes / TViTT
Final Cut Pro is a registered trademark of Apple Inc. DaVinci Resolve is a registered trademark of Blackmagic Design. Adobe Premiere Pro is a registered trademark of Adobe Inc. Avid and Media Composer are registered trademarks of Avid Technology, Inc. AlphaSUB is not affiliated with, endorsed by, or sponsored by any of these companies.
On-device by default. Cloud when you choose it.
Speech recognition, translation and speaker diarization run on the Mac: private, offline, free. Nothing leaves the machine unless you pick a cloud engine for that task.
- On-deviceRecognition, translation, diarizationEntirely on your Mac. Free, no account, no upload.
- OfflineZero egressWorks on a plane. Works on an embargoed title.
- LocalYour own serversOllama, LM Studio, LocalAI, AnythingLLM or MTPLX, on this Mac or another on the network. Free.
- Cloud · ProDeepL and external modelsOpenAI, Anthropic Claude, Google Gemini, Mistral, OpenRouter, DeepSeek or any OpenAI-compatible endpoint, with your own key. AlphaSUB fetches the available models.
- Per taskYou choose, every timeThe engine is picked per job. On-device stays free in every edition.
What the licence unlocks.
Every AlphaSUB project is the same file on Free and Pro. Author and QC on Free, hand it to a Pro finisher for delivery. Nothing is lost in between.
Broadcast & cinema export
EBU STL, SCC, Netflix TTML, Amazon DFXP, iTunes TTML, with pre-export conformance checks.
Video export & render queue
Burned-in subtitles to ProRes and DNx masters, H.264 / HEVC in MOV, MP4 or MKV. Presets, timecode window, watermark, batch queue.
Digital-cinema subtitle assets
ST 428-7 and InterOp assets with subsetted fonts, and the subtitles read back out of an existing DCP.
Blackmagic DeckLink output
Direct SDI / HDMI output. Real-time burn-in for live broadcast and mastering.
Batch export
Multiple tracks and multi-language deliverables in one pass. Season and multi-title packages.
Season Bible
Names, terms and translation choices kept consistent across episodes, with consistency checks.
Cloud AI models
DeepL or an external LLM with your own key for higher-quality translation. On-device stays free.
Live collaboration
Several editors on one project with conflict-free sync. Host or join a session and edit together.
Secure mode
Air-gap the application for confidential content: all network egress blocked while you work.
Digital cinema, in two applications.
AlphaSUB reads DCPs.
AlphaDCP builds them.
Building, encrypting, signing, validating and delivering Digital Cinema Packages is AlphaDCP, sold separately. AlphaSUB still opens a DCP, plays its picture so you spot against the real image, and exports ST 428-7 and InterOp subtitle assets.
In AlphaDCP, right-click a subtitle track and it opens here with the DCP attached. Every save lands back in AlphaDCP as you work.
Discover AlphaDCP →
Free to subtitle. A licence to deliver.
Prices ex-VAT. Each paid plan covers two seats, includes every update, cancel anytime.
Spotting, editing, on-device AI, QC, every everyday and interchange format, DCP subtitle assets.
Broadcast delivery formats, video export, DeckLink, batch, Season Bible, cloud AI.
Digital-cinema mastering: reels, CPL / PKL, encryption, KDM, validation, delivery.
AlphaSUB Pro and AlphaDCP together. Saves €99.
Education: €79 per seat per year, or €499 per year as a site licence deployed to every workstation. Ask about education licensing.
Not for sale yet. Get in early.
Beta access is free: no payment, no card. Each application has its own beta programme. When Pro goes on sale, beta testers get 25 % off their first year. We email a free beta licence once the request is approved.
Download. Spot. Deliver.
Two applications, one project file between them. Both are stable releases; new work lands on the beta channel first.
Requires macOS 14 Sonoma or later · Apple Silicon and Intel · Universal build
All releases ↗