Subtitle Shift API

POST https://api.findutils.com/api/tools/subtitle-shift/execute

Shift every cue in a SubRip (.srt) or WebVTT (.vtt) caption file by one fixed offset, so a track that runs early or late lines up with the audio again. A positive offset delays the captions (they appear later); a negative one advances them. The output keeps the input format, cue text, order and WebVTT cue settings. A cue whose start would go below zero is held at zero and counted; a cue that would end before zero is dropped and counted. Timing only: nothing is stretched, translated or edited.

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Request body

application/json

input

string required

Caption file contents, either SubRip or WebVTT.
offset_ms

integer required

Milliseconds to add to every timestamp. Positive shows captions later, negative earlier. 1500 means one and a half seconds later.

Example arguments

Verified

{
  "input": "1\n00:00:10,000 --> 00:00:12,000\nTen seconds in.\n",
  "offset_ms": 1500
}

curl -X POST https://api.findutils.com/api/tools/subtitle-shift/execute \
  -H "Content-Type: application/json" \
  -d '{
    "input": "1\n00:00:10,000 --> 00:00:12,000\nTen seconds in.\n",
    "offset_ms": 1500
  }'

const response = await fetch('https://api.findutils.com/api/tools/subtitle-shift/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"input":"1\n00:00:10,000 --> 00:00:12,000\nTen seconds in.\n","offset_ms":1500}),
});
const data = await response.json();

import requests

response = requests.post(
    "https://api.findutils.com/api/tools/subtitle-shift/execute",
    json={"input":"1\n00:00:10,000 --> 00:00:12,000\nTen seconds in.\n","offset_ms":1500},
)
data = response.json()

$ch = curl_init('https://api.findutils.com/api/tools/subtitle-shift/execute');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
    CURLOPT_POSTFIELDS => '{"input":"1\n00:00:10,000 --> 00:00:12,000\nTen seconds in.\n","offset_ms":1500}',
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

Also an MCP tool

Call subtitle_shift from Claude, Cursor or any MCP client. Same arguments, same output.

https://mcp.findutils.com

MCP reference

Rate limit: 60 a minute, per IP
Auth: None
REST id: subtitle-shift
MCP name: subtitle_shift
Category: Media
Machine-readable: openapi.json · markdown.md

Request body

Example arguments

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