What's New in Subtitle Edit 5

Subtitle Edit 5 is the Avalonia-based, cross-platform version of Subtitle Edit. It keeps the familiar subtitle editing workflow from the Windows Forms version, but many features were expanded.

Application Platform

• Cross-platform Avalonia UI for Windows, Linux, and macOS — macOS is a new supported platform in SE 5.
• Cleaner, High-DPI-aware UI that scales correctly on modern displays.
• Follow system theme (light, dark, etc.) automatically, or pick a theme manually.
• New Flatpak packaging work for Linux.
• Many new settings, and the settings dialog has a built-in search to quickly find any option.
• Native pick-folder dialog wherever a folder is needed (was missing in the WinForms 4.x line).

Editing and Grid

• Show formatting in grid — formatting tags (italic, bold, color, etc.) can now be rendered visually in the subtitle grid.
• Edit controls Show/Hide/Duration are now optional and can be toggled on/off.
• Deleting many lines at once in the subtitle grid / list view is dramatically faster.
• New Tools → Change formatting dialog for adding or removing italic, bold, underline, and other formatting across selected lines.
• New Tools → Merge two subtitles tool that combines two subtitles (or the loaded subtitle's text + translation) into one bilingual subtitle. Output as SubRip (overlapping pairs stacked as line 1 / line 2) or ASSA with two configurable styles (font, color, outline, shadow, top/bottom alignment) and a live preview.
• AI assistant for the current line — ask a local AI model about the selected line or ask it for a change (fix errors, fit reading speed, more formal/casual, or a free-form request), from the text box context menu or the edit-box toolbar. Runs via llama.cpp, Ollama, or any OpenAI-compatible endpoint.

Video

• New Video → Re-encode tool that re-encodes a video into a format better suited for subtitling work.
• New Video → Cut video tool for trimming video segments directly from Subtitle Edit.
• Video → Burn-in with logo — a logo/watermark image can now be included when burning subtitles into video.
• Many new speech-to-text engines (see Speech to Text below).
• New Video → OCR burned-in subtitle tool that extracts hardcoded subtitles from video via OCR (see Video OCR).
• Improved reading of subtitles embedded in MP4 files.
• PGS position monitor — the binary/image-based edit window has a BDSup2Sub-style position map for image-based subtitles (.sup/.sub/BDN): every subtitle's real rectangle on the video canvas, color coded by zone (active picture / letterbox bars), with configurable content aspect ratio, custom bar height, and title-safe margin.

Sync

• Visual Sync now includes a waveform, making it easier to pick precise sync points.

Waveform and Spectrogram

• Waveform toolbar buttons can be customized, sorted, imported, and exported.
• Waveform themes can be imported and exported.
• Spectrogram style can be changed at runtime — no re-generation needed.
• More customization options for the waveform and spectrogram, including colors, shot-change colors, and visual style.
• Snap to shot changes now reads its snap window from the Beautify time codes profile's red zones, and Shift while dragging temporarily disables the snap.

Beautify Time Codes

• New Tools → Beautify time codes… brings the SE 4 beautifier across, but as a live tool: two stacked waveform visualizers (original / beautified) show the result before you accept it, with prev/next navigation, frame and millisecond deltas, and a per-cue reason line (snapped to shot change · min. gap enforced · min. duration enforced, etc.).
• The full profile editor (zones, chaining, connected-subtitle handling, per-cue gap, presets for Netflix and SDI) is available from the tool window and from Options → Settings → Waveform. Profile edits persist into Settings.json.

Speech to Text

Speech recognition is no longer limited to classic Whisper workflows. Subtitle Edit 5 includes a broader set of local and downloadable engines:

• Purfview Faster-Whisper XXL, CTranslate2, Whisper.cpp (with cuBLAS and Vulkan backends on Windows), OpenAI Whisper, OpenAI-compatible STT, and Const-me's Whisper.
• Qwen3 ASR with multiple GGUF model sizes.
• Crisp ASR variants including GLM, Qwen3, Granite, Omni, Parakeet, Canary, Cohere, Fire Red, Mega, and Kyutai.
• Forced-aligner picker (built-in / Canary CTC / Qwen3 / 12 language-specific wav2vec2 aligners) for word-level timestamps.
• Per-engine advanced parameters and batch transcription improvements.
• Automatic language selection for several newer engines.

See Speech to Text for the current engine list and workflow.

Text to Speech

Text to speech now includes more local and cloud engines:

• Edge-TTS.
• Mistral TTS.
• Qwen3 TTS with downloadable local server builds and models.
• Kokoro TTS with downloadable local server builds and models.
• OmniVoice TTS - a local CPU engine (many languages, voice cloning) with downloadable models.
• Review audio clips, regenerate individual lines, keep regeneration history, and export generated clips with metadata.

See Text to Speech for details.

Auto-translate

Subtitle Edit 5 adds local, downloadable auto-translate engines that run entirely on your own machine:

• Server-managed llama.cpp — Subtitle Edit downloads llama.cpp, manages a local llama-server process, and offers a curated TranslateGemma model picker, so no manual server setup is required. CPU, Vulkan, and CUDA builds are available, and the server can be started and stopped from the Auto-translate window.
• CrispASR MADLAD — a local MADLAD-based translation engine with downloadable models (shown with size and install status), available in both the Auto-translate window and Batch Convert.
• OpenAI Compatible API — a generic engine for any service exposing an OpenAI-compatible chat/completions endpoint (vLLM, KoboldCpp, a llama.cpp server on another machine, cloud providers, ...).

See Auto-translate for the full engine list and workflow.

AI Review

• New Tools → AI review — an AI proofreading pass that catches typos, spelling, grammar, punctuation, and casing errors without rephrasing or changing meaning, tone, or style.
• Runs locally by default — uses a server-managed llama.cpp engine with a downloadable model picker, so no cloud service or API key is required. Ollama and any OpenAI-compatible endpoint are also supported.
• Review before you apply — suggestions are listed as before/after pairs with a per-line reason, grouped by category (Spelling, Grammar, Punctuation, Casing, Other) with filter chips. Tick the ones you want and apply only those.
• Safe by design — formatting tags (<i>, {\an8}, etc.) and line breaks are preserved; suggestions that touch tags are dropped, and large rewrites are flagged for a closer look and left unselected.
• Editable prompt — the instructions sent to the model can be customized (with the subtitle language auto-detected and substituted in).

See AI Review for details.

Batch conversion

• OCR while converting — Batch Convert can turn image-based subtitles into text-based formats in bulk, using nOCR, Binary OCR, Tesseract, Ollama, or PaddleOCR. Language and pixels-are-space settings can be auto-detected for nOCR/Binary OCR, so converting many files with similar fonts needs far less manual setup.
• Local auto-translate in the queue — the new local engines (server-managed llama.cpp / TranslateGemma and CrispASR MADLAD) can be applied directly as a batch conversion step, fully offline.
• More chainable functions — including the new Change formatting (add/remove italic, bold, underline, etc.) alongside the existing fixes, replacements, casing, time-code, gap, merge, and split operations.
• Speech-to-text batch mode — transcribe many media files at once and save the results next to the source files.
• Optimized MKV parsing — reading subtitle tracks from Matroska (.mkv) files is significantly faster, speeding up batch jobs that extract subtitles from many video containers.

See Batch Convert, OCR, and Command Line (seconv).

ASSA Tools

• New Apply advanced effects tool that generates cinematic and creative ASSA override-tag animations (typewriter, karaoke, bounce-in, neon, glitch, rainbow, starfield, rain, snow, fireflies, and more) with real-time video preview.
• Hide layer — individual ASSA layers can now be hidden in the preview to focus on the lines you are working on.
• ASSA filtering — filter and search lines in the ASSA grid by style, actor, layer, or tag content.

Subtitle Formats

• Added IMSC-Rosetta Timed Text subtitle format support.
• New Import CSV/XLSX with custom columns window for spreadsheets that don't fit the standard layout — pick which columns map to start, end, text, etc.

Command Line (seconv)

The seconv headless converter now lives in the main Subtitle Edit repository — it builds, ships, and updates in lockstep with the desktop app.

• Polished terminal UI — colored output with progress per file, summary tables, and a --json mode for CI pipelines and scripting.
• Cross-platform — runs on Windows, Linux, and macOS with only the .NET runtime; no display or GUI required, suitable for servers and Docker.
• Broader feature set — additional time and cleanup operations, OCR engine selection (Tesseract / nOCR / Binary OCR / Ollama / PaddleOCR), container input from .mkv / .mp4 / .mcc, info and lint subcommands for inspection, custom output templates, and POSIX-style flag names (legacy SE 4.x flags still work).

See Command Line (seconv) for usage and examples.

Where to Look Next

• Main Window - updated application layout.
• Audio Visualizer / Waveform - waveform, spectrogram, and shot change tools.
• Third-Party Components - component setup and data folder locations.
• Command Line (seconv) - headless conversion and OCR.