Video subtitles for streaming platform: one WebVTT file per language
Video subtitles for streaming platform operators: upload a WebVTT file per language on each video or episode and let viewers pick the track in the player.
Flicknexs stores uploaded WebVTT subtitle files against each video and episode, one file per language from the admin language catalog, and serves the full track list to the player on every app so the viewer can switch captions during playback.
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Quick answer: Video subtitles for streaming platform use are timed text tracks that a player draws over the picture so viewers can follow dialogue without relying on the audio. Flicknexs lets an admin upload one WebVTT subtitle file per language on each video or episode, keeps a language catalog, and shows a caption selector in the player.
Flicknexs provides video subtitles as part of its white-label OTT platform. Flicknexs stores uploaded WebVTT subtitle files against each video and episode, one file per language from the admin language catalog, and serves the full track list to the player on every app so the viewer can switch captions during playback.
Why subtitles decide whether a title travels
A subtitle track is the cheapest way to make a title watchable by a viewer who does not share its spoken language, watches on mute, or has a hearing impairment. It is also a legal question in several markets, where accessibility rules for on-demand video ask for captions on a growing share of the catalog. An operator who ships a title without captions is quietly choosing a smaller audience for it. The work is not large: a translator produces a timed text file, and the platform has to store it, list it and hand it to the player.
What goes wrong in practice is rarely the translation. It is the plumbing. Files arrive in the wrong format, the timing drifts after a re-encode, a series has captions on episode one and nothing on episode four, or the mobile app shows a track the web player cannot find. Flicknexs treats subtitles as part of the title record rather than a per-device setting, so the same list of languages is attached to the video wherever it plays. That is the design decision this page explains, along with what the admin exposes and what it leaves to you.
The format Flicknexs expects is WebVTT, the Web Video Text Tracks format that the World Wide Web Consortium publishes as the WebVTT specification and that browsers and mobile players read natively. If your captions arrive as SRT or a broadcast format, convert them to WebVTT before upload. This page covers the per-language upload flow, where the caption selector appears, what the AI transcription job produces and does not produce, the limits you should plan around, and a launch checklist for a subtitled catalog.
How subtitles work on Flicknexs
The table below lists what the admin exposes for captions, how the player uses it, and why each piece matters when you run a catalog in more than one language.
Per-video upload
Each video record has a subtitle area where the admin uploads a WebVTT file per language.
Per-episode upload
Series episodes carry their own subtitle uploads, so each episode can have a different set of languages.
Language catalog
The admin keeps a list of languages; every subtitle upload is tagged with one entry from that list.
Multiple tracks per title
A single video or episode can hold several subtitle files, one for each language you have translated.
In-player selection
The player lists the available caption tracks and lets the viewer switch or turn them off during playback.
WebVTT expected
The player reads WebVTT; the upload form does not check the file type, so upload WebVTT files only.
AI transcription metadata
A transcription job returns text, detected language, duration and timed segments stored as metadata for search and summaries.
Same tracks on every app
The track list is part of the title data the web player and the device apps read.
Source: Flicknexs platform documentation and architecture specification, 2026-09-03.
The mechanics: what the admin exposes and what the player does
Subtitles on Flicknexs are simple by design. A caption file is a piece of data attached to a title, tagged with a language, and handed to whichever player is asking for that title. The items below walk through each part of that chain.
The subtitle upload on a video record
When you open a video in the admin, the subtitle area sits alongside the other metadata for that title. You pick a language from the catalog, choose the WebVTT file from your computer, and save. The file is stored with the video and listed in its track set. Repeat for each language you have. Removing a track is the reverse: delete the entry and the player stops offering that language on the next load.
Episodes are captioned one at a time
A series is a container; the episodes are the playable items, so subtitle uploads happen on the episode record rather than on the series. This is deliberate. Translation schedules rarely line up neatly, and a distributor often has French captions for the first six episodes before the last four are ready. Each episode carries its own track list, and an episode with no uploads simply shows no caption selector.
The language catalog behind the picker
The admin holds a catalog of languages that the whole platform shares. Subtitle uploads are tagged from that list, and the label the viewer sees in the player comes from the same place. Keeping this list tidy is worth ten minutes of your time before launch: if two admins add "Portuguese" and "Português" as separate entries, viewers will see both, and one of them will usually be empty on any given title.
What the player does with the track list
When a viewer starts a title, the player receives the video manifest and the list of subtitle tracks with their language labels. It shows a caption control, lists the languages, and lets the viewer choose one or switch captions off. Selection happens client-side; the video stream itself does not change. The player draws the cues at the times written in the WebVTT file, which is why timing must match the encoded video.
WebVTT and why the upload does not check it
The upload form accepts a file and stores it; it does not parse or validate the contents. That means an SRT file with a .vtt extension will upload without complaint and then fail to render, with no error surfaced to the viewer. Treat the format rule as yours to enforce. A valid WebVTT file starts with the line WEBVTT, uses a period before milliseconds, and separates cues with blank lines. Most subtitle editors export it directly.
AI transcription is metadata, not captions
Flicknexs can run an AI transcription job on a video. The job returns the spoken text, the detected language, the duration and a list of timed segments, and the platform stores those as metadata used for search and summaries. It does not write a WebVTT file and it does not add a caption track to the player. If you want captions from that transcript, a person exports and times it in a subtitle tool, then uploads the result.
How to set up subtitles in the Flicknexs admin
Five steps take a catalog from no captions to a per-language track list the player can offer. Do them in this order; the language catalog has to exist before any upload can be tagged.
- 1
Build the language catalog first
Open the language settings in the admin and add every language you intend to caption in, using one entry per language and a label your viewers will recognize. Decide on naming now: native name, English name, or both. Every later upload is tagged from this list, and renaming an entry later changes the label on every track that uses it.
- 2
Prepare WebVTT files that match the encoded video
Export captions from your subtitle tool as WebVTT, one file per language per title. Check the first line reads WEBVTT and that timestamps use a period before milliseconds. Confirm timing against the file you actually uploaded to Flicknexs, not an earlier cut; if the master was trimmed before transcoding, cue times shift and captions will lead or lag the dialogue.
- 3
Upload tracks on each video and episode
Open the video record, or the episode record for a series, find the subtitle area, choose the language from the catalog, select the file and save. Repeat per language. Name your files in a consistent pattern such as title-slug.fr.vtt so that whoever uploads next month can tell what has been done from the file list alone.
- 4
Play the title on the web player and one app
Open the title as a viewer, start playback and open the caption control. Every language you uploaded should appear; pick each one and confirm cues render at the right moments. Then do the same on at least one of the device apps included in your plan, because the on-screen selector sits in a different place on a TV remote than on a phone.
- 5
Make captioning part of the publishing routine
Add a subtitle line to whatever checklist your team uses before a title goes live: which languages are required, which are done, and who signs off. Titles published without captions are the most common gap we see, not broken tracks. If a language is still in translation, publish with the tracks you have and add the rest as they arrive.
Limits, tradeoffs and what subtitles on Flicknexs do not do
The feature is deliberately narrow: store timed text per language and hand it to the player. The items below are the boundaries you should plan around rather than discover on launch day.
No automatic caption generation
The AI transcription job produces metadata for search and summaries, not caption tracks. There is no button that turns a video into a WebVTT file, and there is no machine translation of an uploaded track into other languages. Human or third-party caption production remains part of your workflow, and the platform stores the result. Budget for it per title and per language.
No format conversion or validation on upload
The upload stores whatever you give it. SRT, TTML, SCC or a broadcast caption file will be accepted by the form and ignored by the player. Convert to WebVTT before upload and test playback after. Because nothing warns you, a wrong-format track can sit on a live title for weeks unless someone plays it with captions on.
No caption styling controls in the admin
Font, size, color, background and position of caption text are not exposed as operator settings. Captions render in the default style of each player, and viewers on some devices can adjust caption appearance from the device accessibility settings. If a brand guideline demands a specific caption look, that is a customization request, not a toggle.
On-demand titles only
The subtitle upload lives on video and episode records. Live streams and linear channels do not have a subtitle upload, and there is no live captioning path in the platform. If a live event needs captions, plan to caption the recording after the event and attach the tracks to the on-demand version.
One track per language per title
The language catalog tags each upload with a single language, and a title holds one file per language entry. Variants such as "English for the hearing impaired" alongside plain English need separate catalog entries to coexist on one title. That works, but it means the catalog grows with every variant you decide to support, so decide the variant policy before the catalog fills up.
A worked example: a film distributor captioning a catalog
A concrete case shows where the effort goes. The operator below is fictional; the steps are the ones a real distributor would follow on Flicknexs.
Imagine an independent film distributor with a catalog of about two hundred features and a handful of documentary series, selling to viewers in three regions with different first languages. The distributor already owns subtitle files for most titles, because theatrical and broadcast deals required them, but they arrive in a mix of formats from different labs. Before touching the platform, the distributor converts every file to WebVTT with a subtitle tool, checks the timing against the master that was uploaded for transcoding, and names each file by title slug and language code.
In the admin, the team creates four language entries: English, French, Spanish and Portuguese, with the native name shown to viewers. They upload tracks title by title, prioritizing the films that carry the most traffic in the regional reports. For the documentary series, each episode gets its own uploads, and the team publishes episodes with two languages ready rather than holding the season for all four. The AI transcription job runs on English-language titles so search can match spoken phrases, but the team knows those transcripts do not become caption tracks.
At launch, a viewer in the Portuguese-speaking region opens a French film, taps the caption control and picks Portuguese. Nothing changes on the video stream; the player simply draws the Portuguese cues. The same title on the Android TV app offers the same four languages from the remote. When the distributor later adds a hearing-impaired English variant, they add a fifth catalog entry and upload the new file alongside the existing English track, and the distributor never has to touch device settings to make it appear.
Launch checklist for a subtitled catalog
Run this list before a captioned title goes live. Each item is a real failure we have seen on operator platforms, and each takes minutes to check.
- Every language you plan to caption exists once in the admin language catalog, with the label viewers should see.
- Every subtitle file starts with the line WEBVTT and uses a period before milliseconds in each timestamp.
- Cue timing was checked against the exact video file uploaded for transcoding, not an earlier edit or a trimmed master.
- Each video and each episode of a series has its required languages uploaded, with none left as "coming later" by accident.
- Playback with each caption track was tested on the web player and on at least one device app from your plan.
- The caption control is visible on the TV app remote flow, and switching languages during playback works without a restart.
- Files are named by title slug and language code so the next admin can audit coverage from the file list alone.
- The team knows AI transcription produces search metadata, not caption tracks, and nobody is waiting for captions to appear on their own.
- A subtitle line is on the publishing checklist with an owner, so new titles do not ship without their required languages.
- Any hearing-impaired or regional variant has its own catalog entry, so two tracks in the same language do not overwrite each other.
How subtitles fit with the device apps and with monetization
Captions are stored once and read everywhere, which keeps the device and revenue sides simple. Two neighboring pages carry the detail this section touches on.
Because subtitle tracks are part of the title record, the web player and the Android, iOS, Android TV and Fire TV apps that come with your plan all read the same list, and the TV apps you add on read it too. There is no per-platform caption setup. What does differ is the control layout: a phone shows a caption icon in the player chrome, a TV app puts the selector in the remote-driven overlay. Test the flow on each app you ship. The multi-language video page explains how captions relate to interface language and audio language, which are separate layers, and the video transcoding page covers how the video ladder is produced, which is why cue timing must match the encoded file.
On the revenue side, captions do not change how a title is sold. A pay-per-view purchase, a rental window or a subscription plan grants access to the title, and every subtitle track on that title comes with it; there is no per-language pricing and no caption-only entitlement. What captions do change is reach. A title captioned in a second language can be marketed in a second region without a dubbed version, and the video paywall page describes the per-title pricing you would attach to that wider audience. If you also restrict titles by country, the geo-fencing page explains how allow and block lists interact with a catalog that has been captioned for regions you do not serve.
Which plan includes subtitles
Standard layers
Subtitle upload, the language catalog and the in-player caption selector are part of every plan; there is no subtitle add-on and no per-language fee. What differs by plan is which apps show the caption control to your viewers. F1 Standard is the web-only plan, with 300 GB of storage and 20 TB of bandwidth yearly; see our pricing page for current plan and pricing details. F1 Standard includes 300 GB of storage and 20 TB of bandwidth yearly for website streaming; see our pricing page for current plan and pricing details.
Pricing & billing
F2 Super includes 300 GB of storage and 20 TB of bandwidth yearly, and adds native Android and iOS mobile apps; see our pricing page for current plan and pricing details. F3 Premium includes 1 TB of storage and 10 TB of bandwidth monthly, and adds Android TV and Fire TV apps; see our pricing page for current plan and pricing details. F4 Enterprise includes 2 TB of storage and 20 TB of bandwidth monthly and adds dedicated support to everything in F3; Samsung, LG, Roku and Apple TV apps are add-ons on any plan. See our pricing page for current plan and pricing details. TV apps are available as add-ons on any plan, allowing you to expand your reach to more devices; see our pricing page for current plan and pricing details.
Annual savings
Subtitle files are small, so they do not move the storage line on any plan in a way you will notice; the video files themselves do. Plans are flat fees and Flicknexs takes no commission on your revenue; payment-gateway fees are between you and your gateway. See our pricing page for current plan and pricing details. Yearly billing on F1 to F4 costs less per month than monthly billing; see our pricing page for current plan and pricing details.
Conclusion: what to do next
Already on Flicknexs
If you already run on Flicknexs, open the language catalog today and confirm it has one clean entry per language you caption in. Then pick your ten most-watched titles from the content analytics and check each one has every required track. Play one of them with captions on from a TV app. That single pass catches most of the caption problems operators report, and it costs less than an hour.
Choosing a platform
If you are choosing a platform, ask two questions of every candidate: which caption format does the player read, and does the caption list live with the title or with each app. On Flicknexs the answers are WebVTT and with the title. Ask also what the AI transcription actually produces; on Flicknexs it is search metadata, not caption files, and we would rather you know that before you sign than after.
Before a rights call
Read the multi-language video page next, because captions are one of three language layers and buyers often conflate them. Then read the video transcoding page to understand why caption timing must match the encoded file. If your catalog is sold by region, the geo-fencing page explains the country rules that decide who sees a captioned title at all.
Frequently Asked Questions
Everything you need to know about subtitles on Flicknexs.
Yes. Subtitle upload per video and episode, the language catalog and the in-player caption selector are included in every plan, with no add-on and no per-language fee. Plans differ in which apps your viewers can use, according to our pricing page, not in whether those apps show captions.
Upload WebVTT files. The player reads WebVTT, and the upload form does not validate the file type, so a file in another format such as SRT or TTML will be stored but will not render. Convert to WebVTT with any subtitle editor before uploading, then test playback with the track selected.
Yes. Subtitle tracks are attached to the title, not to a device, so the Android TV and Fire TV apps included by plan and the add-on TV apps read the same track list as the web player. The caption selector sits in the remote-driven player overlay rather than a touch control, so test the flow on each TV app.
No. The AI transcription job returns text, detected language, duration and timed segments, and Flicknexs stores those as metadata for search and summaries. It does not write a WebVTT file or add a caption track. A person exports the transcript into a subtitle tool, times it and uploads the result.
One track per language entry in the admin catalog, with as many entries as you create. A title can therefore carry every language you have translated. Variants such as a hearing-impaired version alongside plain English need their own catalog entries so both tracks can sit on the same title.
On each episode. A series is a container and episodes are the playable items, so each episode record has its own subtitle uploads and its own language list. This lets you publish episodes as translations arrive rather than holding a whole season for the last language.
Almost always because the WebVTT file was timed against a different cut than the one uploaded for transcoding. If the master was trimmed or a slate was removed, every cue shifts. Retime the file against the video actually in the admin, re-upload, and check playback from the start and from a mid-title seek.
Not through a Flicknexs setting. The admin does not expose caption styling, and captions render in each player default style. Some devices let the viewer adjust caption appearance from the device accessibility settings, which the player respects where the platform supports it, but that is device behavior, not a platform control.
No. The subtitle upload lives on video and episode records only, and there is no live captioning path. For a live event that needs captions, caption the recording afterwards and attach the WebVTT tracks to the on-demand version of the event once it is published.
No. The video stream is unchanged; the player fetches the small text file for the chosen language and draws the cues client-side. Subtitle files are a few kilobytes each and do not meaningfully affect the storage and bandwidth allowances that our pricing page lists for each plan.
Access to a title, whether by subscription plan, pay-per-view purchase or rental window, grants access to every subtitle track on that title. There is no per-language pricing and no caption-only entitlement. Captions change who can enjoy the title, not how it is sold.
Tracks tagged with that entry lose their label and should be treated as unavailable, so audit which titles use a language before removing it. The safer move is to rename an entry rather than delete it, since renaming updates the viewer-facing label on every track that uses it in one step.