Subtitling has its own vocabulary, and Fluen Studio adds a few words of its own. This page defines the ones you will meet in the app, in the FAQ and in these guides. Jump to a letter, or read it through once and the rest of the Help Center will make more sense.
A
- AI Wordsmith also: Auto-Wordsmith
- The step that rewrites a translated subtitle when it runs too long for the time it is on screen. It runs automatically during translation: some languages need more words than the source (English to German, for instance), so the AI rephrases or condenses the line to fit the reading-speed and line limits while keeping its meaning. It only applies to translations; captions stay verbatim.
- Aspect ratio
- The shape of the video: landscape (16:9), square (1:1) or portrait (9:16 and similar). Fluen adapts the default characters per line and font size to it, so vertical videos get shorter lines and smaller text than widescreen ones.
B
- Background also: plate, backing plate
- What sits behind the subtitle text, part of the caption style. In the Customize tab of the Caption style panel you can give the text an Outline or a Shadow (with an optional halo), put a box behind each line (Lines), one Plate behind the whole caption or a full-width Band, and set its corners and padding. A separate Frame section darkens the bottom of the picture (Scrim), adds a band across it, or adds Letterbox bars. See Caption styles and dynamic captions.
- Burn-in also: burned-in, hardcoded, open captions
- Rendering the subtitles into the picture itself, so they are part of the video and cannot be switched off. Fluen exports a burned-in MP4 in 720p, 1080p, 4K or the original resolution. The opposite is a separate subtitle file (SRT, VTT and so on) that the player overlays. See Export video with burned-in subtitles.
C
- Caption style also: style, preset
- How a track's subtitles look and move: font, size, colours, outline, shadow, background, position, speaker labels and, for animated styles, motion. You change it from the Caption style button under the video, starting from one of more than 30 built-in presets. It is saved per track, used by the editor, share and review links and the burned-in export, and a workspace can set the style new videos start with. Subtitle files such as SRT carry no style. See Caption styles and dynamic captions.
- Captions vs. subtitles vs. translations
- In Fluen Studio, captions are the subtitles in the language spoken in the file (the source language). Translations are the tracks in other languages. Subtitles is the general word for both. The broader distinction between closed captions and subtitles is explained in this article.
- Characters per line CPL
- The maximum number of characters allowed on one subtitle line, including spaces and punctuation. The default depends on the language and the aspect ratio: 42 for English on a landscape video, fewer for portrait videos and for languages with denser scripts. You can change it on the upload screen, with the editor's Rules button, and per language in Workspace Settings under Subtitle Limits. See Font size and characters per line.
- Characters per second CPS, reading speed
- How fast a viewer has to read a subtitle: its length in characters divided by the time it stays on screen. Every cue in the editor shows its CPS; on translation tracks a warning appears when a cue is above the comfortable limit for that language (20 for most languages), and the cue is listed in the issues list as Too fast.
- Comment
- A note pinned to one subtitle, or to the whole video, in the editor's Comments panel. Comments are threads: reply underneath and mark them Resolved when the change is made. They work on every plan, and anyone with a Can comment share link can leave one without an account. A comment marked Internal is seen only by your workspace. See Comments, reviews and approvals.
- Credit minute also: minute, credit
- The billing unit. Each minute of subtitles produced costs one credit minute: once for the captions and once for every translation language. Files are rounded to the nearest whole minute. See How Fluen pricing works.
- Cue also: subtitle, segment, block
- One subtitle: a start time, an end time and one or two lines of text. A track is a list of cues. In the editor each row of the list is a cue, and each highlighted region on the waveform is the same cue's timing.
D
- Dash marker
- One of the three ways to show speakers: a dash at the start of the cue each time the speaker changes, without naming anyone. The others are named speaker labels and no markers at all.
- Diarization also: speaker detection, speaker identification
- Working out who is speaking when, and assigning each cue to the right person. See Speaker identification.
- Dynamic captions also: animated captions, word-by-word captions, karaoke captions
- Captions that move with the speech: words appear, light up, fill in or get a highlight as they are spoken, instead of the whole caption showing at once. Fluen has 14 animated presets (Highlight, Keynote, Rise, Rolling Lines and more) on the Animated shelf of the Caption style panel, and the Motion tab adjusts how words arrive and how the word being spoken is marked. They play the same way in burned-in exports. See Caption styles and dynamic captions.
E
- Engine also: transcription engine, subtitle segmentation
- The model that does a particular job. The transcription engine turns speech into text: ElevenLabs Scribe v2, Speechmatics, Deepgram Nova-3, AssemblyAI or OpenAI Whisper. Subtitle segmentation is Fluen's own step that turns that text into well-timed, well-split cues (Standard or Smart). Both default to Auto (Recommended): for transcription, each language goes to the engine that did best in our regular tests; for segmentation, the method is picked by file length and language. Both can be pinned in Workspace Settings, under Subtitle Defaults. Our overviews of the transcription engines and of subtitle segmentation go into detail.
- Expired media also: archived
- A media whose video or audio file has been removed from our servers after the retention period of your plan (30 days on Free, 90 days on Premium, 180 days on Team, one year on Enterprise). The entry stays in your library and its subtitle tracks can still be exported; the editor preview and new exports of the video are no longer possible.
- Export
- Getting your work out of Fluen. There are three kinds: Video with Subtitles (a burned-in MP4), Subtitles File (SRT, WebVTT, TTML, SSA, iTunes Timed Text, SubViewer or EBU STL) and Text Transcript (Word, PDF or plain text).
G
- Glossary
- A list of terms, per workspace, with the spelling you want in captions and the translation you want in each language: names, brands, acronyms, product names. It is applied automatically to every file processed after you add the entry. See Set up a custom glossary.
I
- Issues list
- The editor's list of subtitles that break the limits: lines over the characters-per-line limit (Too long) and, on translations, subtitles faster than the comfortable reading speed (Too fast). A counter in the status bar at the bottom of the editor opens it; click a row to jump there, or press F8 and Shift+F8 to step through. See Font size and characters per line.
L
- Layout
- The old name of the editor's Rules button.
- Lines per cue also: max lines per caption, LPC
- Whether a cue may use one line or two. Two is the usual choice; one keeps captions compact on vertical videos or when the picture matters more.
M
- Media
- An uploaded video or audio file together with everything attached to it: its caption track, its translation tracks, its style and its exports. Your library is a list of media.
- Multi-language audio
- An upload option for files in which more than one language is spoken. It tells the transcription to expect switching between languages instead of forcing everything into the source language.
- My Exports
- The page, in the left sidebar, where burned-in video exports are listed and downloaded. Exported videos are kept for 90 days.
O
- Overflow indicator
- The red outline and tint the editor paints on the part of a subtitle that falls outside the video frame. It means the text is too wide for its position or size and will be cut off in a burned-in export. Fix it by lowering the characters per line, reducing the font size or moving the caption.
P
- Post-editing also: review, In Review
- Checking and correcting a track by hand after the AI has produced it. With post-editing on, the workflow pauses after transcription (and, optionally, after translation) and the track waits In Review until you click Complete in the editor. It can be on or off per upload, and by default per workspace (Review before translating and Review translations in Subtitle Defaults).
- Preset style preset
- A ready-made caption style. Fluen has more than 30, on two shelves of the Caption style panel: Static (captions that appear whole, such as Classic, Broadcast or News Bar) and Animated (dynamic captions, such as Highlight or Keynote). A preset sets the font, colours, background and size, fitted to the picture, and for animated ones the motion. It never changes the text or how it is split into lines.
R
- Reprocessing
- Regenerating a track without uploading the file again. The Rules button re-splits the existing text with new line settings in seconds; on caption tracks, the Troubleshoot menu can also rerun the transcription with a different AI engine once. Neither costs credits, and both overwrite manual edits. See Reprocess a track with new settings.
- Review & approval
- The formal review on the Team plan. Send for review invites a reviewer by email to a private link, valid for 7 days and needing no account, where they can comment, suggest new wording and finally Approve or Request changes. Each language is approved separately, and editing the content afterwards asks for re-approval. See Comments, reviews and approvals.
- Review link also: share link, public link
- A web page for one track (or all language versions of a media) that anyone with the link can open for 72 hours, with no account. You choose what they can do: Can view lets them watch and read the subtitles; Can comment also lets them leave notes on individual subtitles. Nobody can edit or download through it. See Share a track for review.
- Rules formerly: Layout
- The editor toolbar button that sets how the text of a track is split into cues and lines: the characters per line and the maximum lines per cue. Changing either for an existing track triggers a reprocessing that overwrites manual edits.
S
- Safe zone Social Media Safe Zone
- On portrait videos, a guide line at three quarters of the height that keeps captions clear of the buttons and text that social apps draw over the bottom of the screen. Captions snap to it when you drag them; Always at the bottom, under Workspace Settings, Caption styles, Rules for every style, turns it off for new videos.
- Segmentation also: auto-segmentation
- Turning a raw transcript into cues: deciding where each subtitle starts and ends and where the line breaks go. Fluen does this the way a professional subtitler would, following the grammar of each language, so lines do not break between an article and its noun or a first name and a surname.
- Source language / target language
- The source language is the one spoken in the file; the captions are in it. Target languages are the ones you translate into.
- Speaker labels
- Named speakers, one of the three ways to show who is speaking (Names in Subtitle Defaults, the editor's Speakers panel and the export windows). Subtitle files carry the name at the start of each cue in
[Speaker Name]format. On the video, in the editor and in burned-in exports, the caption style draws the name as a label of its own, unless you choose [Name] in text. In the subtitle list each speaker has a colour so you can rename or reassign quickly; the colour appears only there. - Style
- Short for caption style. A style you customize can be saved under a name and is then shared with everyone in the workspace; a translation follows the style of its caption track until you give it one of its own.
T
- Timestamp offset
- An export option that shifts every cue by a fixed amount of time, useful when the subtitles were made from a trimmed segment and must line up with a longer edit.
- Top-up minutes
- Extra credit minutes bought on top of a plan. They never expire and are used once the plan balance is empty. Buying them requires an active subscription.
- Track
- One language version of a media's subtitles. Every media has a caption track and can have any number of translation tracks. Each track has its own status, editor, style and exports.
- Turnaround time TAT
- How long processing takes from upload to finished track. As a rule of thumb, less than half the duration of the file; burned-in video exports take about a quarter to half of the duration on top.
W
- Waveform also: timeline
- The timeline along the bottom of the editor: frames from the video, the audio wave and the text of each subtitle. Click anywhere on it to jump to that moment, and drag the edges of a subtitle to change when it starts and ends.
- Workspace
- A container for media and the settings that apply to them: Subtitle Defaults, Subtitle Limits, the glossary, caption styles and (on Team plans) members with their permissions. You can create several, one per client or project, from My Workspaces in the sidebar.