Step 1 / source
Add the source media
Source intake
Drop one media file here
Choose the SRT track required by a web video or VTT-compatible workflow.
UTF-8 SRT1 SRT / 2 MB
Checking publication status before file selection...
TEMPORARY MEDIA WORKSPACE / SRT TO VTT
SRT to VTT
Convert validated UTF-8 SRT cues into a WEBVTT file with dot-millisecond timestamps and normalized cue separation.
Request-scoped temporary processingAdd one UTF-8 SRT file up to 2 MB containing no more than 10,000 valid, ordered subtitle cues.No account required
Local API readinessMedia service ready
One bounded job runs per API worker by default.The processor required by this tool is available, and this worker can accept a temporary job.
1 SRT / 2 MB
Temporary server workspace
The selected bytes are sent only to the Nirmion media API for this request. Processing uses a private temporary workspace rather than permanent catalogue storage.
Request-scoped cleanup
Server-side source and result files are removed when the response stream closes. Re-downloads use the result Blob retained only in this browser tab.
Original stays unchanged
Nirmion writes a separately named result containing nirmion_tools and never overwrites the selected source file.
Know the product contract
What goes in, what changes, what comes back
Every media page documents the accepted source, the selected FFmpeg transformation, the output container, and the limits that can affect the job.
Prepare the source
Validate the complete SRT against the exact media cut first, including its first cue, final cue, line breaks, language, and timing.
Apply one operation
Sequential SRT numbers are omitted, comma milliseconds become dots, a WEBVTT header is added, and cue text remains in order.
Receive a separate file
Load the VTT in the target player and check language, timing, line breaks, and supported inline tags.
Plain-language method
How SRT cues map to WebVTT
Container conversion does not improve synchronization or caption writing and does not create advanced WebVTT styling.
- 01Choose valid source media
Validate the complete SRT against the exact media cut first, including its first cue, final cue, line breaks, language, and timing.
- 02Review the operation settings
No settings are required because this conversion does not invent VTT positioning or style blocks.
- 03Inspect and download the result
Load the VTT in the target player and check language, timing, line breaks, and supported inline tags.
Useful when
Practical jobs this tool handles
- Prepare captions for an HTML video track.
- Convert an editor export for a VTT-only platform.
- Create a web-review subtitle copy.
Before processing
Check the source and output choices first
- Use the matching media version.
- Confirm valid SRT timing.
- Test the result in the destination player.
- Review inline tags for compatibility.
Container and codec
Understand the output format
The output contains cue text and timing only; STYLE and REGION authoring is outside this tool.
Know the boundary
Player behavior still varies
A structurally valid VTT does not guarantee every platform supports the same tags, positioning, or accessibility workflow.
Quick answers
Questions before you process media
These answers describe the actual upload, FFmpeg processing, download, and temporary-retention contract.
Are cue numbers kept?
No. WebVTT does not require SRT sequence numbers.
Are timestamps changed?
Values stay the same while punctuation changes to VTT format.
Are styles generated?
No.