Speech-to-Text APIs
How can I export Gladia transcripts to SRT/VTT for subtitles with accurate timing?
6 min read
Most subtitle issues start with bad timing. Even if your transcript is accurate, misaligned subtitles break the viewing experience, hurt comprehension, and make your product feel unreliable. With Gladia, you already get precise word-level timestamps; the missing piece is exporting that data into clean SRT or VTT files.
Quick Answer: You export Gladia transcripts to SRT/VTT by reading the word-level timestamps from the API response, grouping them into subtitle segments, then formatting them into
.srtor.vtttext files. A small post-processing script (Python/Node/etc.) handles the conversion and ensures accurate timing for each subtitle cue.
Frequently Asked Questions
How do I get timestamps from Gladia that are accurate enough for subtitles?
Short Answer: Use Gladia’s word-level timestamps and (optionally) diarization from the transcription API response; this gives you start and end times for each word and speaker, which you can aggregate into subtitle segments.
Expanded Explanation:
Gladia’s API returns transcripts with a timestamp for every word, plus optional speaker diarization (“who said what?”). That’s exactly what subtitle engines need: precise timing boundaries, not just a block of text per minute. For subtitles, you typically group words into short, readable chunks (1–2 lines, ~1–6 seconds each) and then use the earliest word start time and the latest word end time in that chunk as the subtitle cue timing.
Because Gladia is designed for real-world audio—telephony (8 kHz) calls, meetings, crosstalk—you don’t need to re-align the audio afterward. You directly map the returned timestamps to SRT/VTT format and get subtitles that stay in sync even on noisy, multilingual recordings.
Key Takeaways:
- Gladia returns word-level timestamps suitable for frame-accurate subtitle timing.
- You can also use diarization metadata to label or split subtitles by speaker if needed.
What’s the process to convert a Gladia transcript into SRT or VTT?
Short Answer: Call Gladia’s transcription API, parse the word-level timestamps from the response, batch words into subtitle segments, then write those segments to .srt or .vtt using the standard timecode formats.
Expanded Explanation:
From an engineering perspective, subtitle export is just one extra post-processing step on top of transcription. Once you have the Gladia JSON response, you loop over words, decide when to start a new subtitle (e.g., max duration, max characters, punctuation break), and then emit formatted cues.
SRT expects HH:MM:SS,mmm timecodes; VTT expects HH:MM:SS.mmm. You can generate both from the same data. Most teams implement this in a small, reusable function inside their media pipeline, so any audio/video processed via Gladia can instantly get subtitles in both formats.
Steps:
- Transcribe audio with Gladia:
- Use the async transcription API (REST) and enable word-level timestamps (default for Gladia) and diarization if you need speakers.
- Parse the response:
- Extract the ordered list of words, each with
startandendtimestamps (and optionalspeaker).
- Extract the ordered list of words, each with
- Segment and export:
- Group words into subtitle “chunks” based on duration, length, and punctuation.
- Convert timestamps to SRT/VTT timecodes and write them as
.srtor.vttfiles.
What’s the difference between SRT and VTT when exporting from Gladia?
Short Answer: SRT uses a slightly older, simpler format (HH:MM:SS,mmm), while VTT is web-native (HH:MM:SS.mmm) and supports richer styling. You use the same Gladia timestamps for both; only the output syntax changes.
Expanded Explanation:
SubRip (SRT) and WebVTT (VTT) are conceptually identical: ordered blocks of timed text. The core difference is syntax and feature support. SRT is ubiquitous in broadcast and offline video tools; VTT is the standard for HTML5 <track> subtitles and can carry styling, positioning, and metadata.
From Gladia’s perspective, nothing changes: word-level timestamps and diarization are format-agnostic. Your conversion layer simply decides which output syntax to use. Most platforms generate both: SRT for downloads and editing tools, VTT for web playback.
Comparison Snapshot:
- Option A: SRT
- Time format:
00:01:23,456 - Simple, widely supported in editing tools and legacy players.
- Time format:
- Option B: VTT
- Time format:
00:01:23.456 - Web-native, supports styling and metadata.
- Time format:
- Best for:
- SRT: offline editing and distribution.
- VTT: browser-based players and modern streaming apps.
How do I implement SRT/VTT export with Gladia in my app?
Short Answer: Wire Gladia’s async transcription into your backend, then add a post-processing step that converts the JSON transcript into SRT/VTT, exposing the files via your API or as downloadable assets.
Expanded Explanation:
In a typical architecture, your media pipeline already takes an audio/video file, sends it to Gladia, and stores the transcript. Subtitle export is just another output on that same pipeline. You don’t need a separate service—just a formatting layer that runs once per completed transcript.
For production use, you’ll want to handle long files, multilingual content, and diarization carefully. That means tuning your segmentation rules (e.g., max characters per subtitle, line breaks on punctuation) and ensuring your export respects language script (e.g., right-to-left languages, non-Latin scripts). Once done, you can use a single Gladia integration to power transcription, analytics, and subtitles.
What You Need:
- A transcription job using Gladia’s API (REST for async, with word-level timestamps).
- A small SRT/VTT formatter in your stack (Python, Node, Go, etc.) that:
- Iterates words in order.
- Groups them into segments.
- Emits valid SRT/VTT files.
How can precise SRT/VTT subtitles from Gladia improve my product or workflow?
Short Answer: Accurate subtitles with reliable timing make your media searchable, accessible, and automation-ready—without bolting on a separate subtitle engine or dealing with misaligned captions.
Expanded Explanation:
If you’re building media tools, meeting intelligence, or CCaaS products, subtitles are not just an accessibility checkbox. They’re an interface to your data. With Gladia as the backbone, you get one API that powers transcripts, subtitles, diarized summaries, and downstream automation from the same high-fidelity text.
Word-level timestamps let you map subtitle segments back to exact audio ranges. That means:
- Click-to-seek in video editors.
- Subtitle-based navigation for long webinars.
- Triggering actions (e.g., highlights, chaptering) based on precise time ranges.
Because Gladia is optimized for telephony, noise, accents, and multilingual code-switching, your subtitles stay usable in the same conditions where other STT systems collapse—so your UI, summaries, and CRM syncs continue to behave as expected.
Why It Matters:
- Higher trust in your UI: Subtitles stay in sync with speech, reinforcing that your summaries, highlights, and analytics are grounded in real words, not guesses.
- Single integration surface: One Gladia API gives you transcripts, timestamps, and multilingual support for 100+ languages—no separate subtitle vendor, no extra timing alignment step.
Quick Recap
To export Gladia transcripts to SRT or VTT with accurate timing, you rely on the word-level timestamps already included in the API response. You group words into readable subtitle segments, convert their start and end times into SRT/VTT timecodes, and output .srt or .vtt files from a small post-processing script. This gives you production-grade subtitles—aligned to real-world audio conditions—that can power accessible playback, precise video navigation, and downstream automation from the same Gladia integration.