Find position of substring
Finding the first occurrence of a phrase is the first step in almost every text pipeline: you locate a marker, then slice, parse, or highlight from that character index.
Run — free
This find-position-of-substring tool takes your source text and a non-empty search term and returns the zero-based character index of the first literal match, plus whether it was found, the exclusive end offset, and the one-based line and column so you can jump to the hit in an editor. Optional start lets you resume after a previous match. Optional case-insensitive matching covers mixed-case drafts. Empty search terms fail with invalid input so bulk jobs never treat the empty string as a match at every offset. The free browser widget runs on your device; the prepaid API charges $0.002 per successful item when servers and SDKs need the same locator in bulk.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
How do I use this capability?
Complete the fields above and run it on this page. The form highlights anything that needs attention.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/str/index-of \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"text":"The kit parses logs: ERROR at line 12, then INFO, then ERROR again.","find":"ERROR"}'const res = await fetch("https://api.kit.forhosting.com/str/index-of", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"text": "The kit parses logs: ERROR at line 12, then INFO, then ERROR again.",
"find": "ERROR"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/str/index-of",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"text": "The kit parses logs: ERROR at line 12, then INFO, then ERROR again.",
"find": "ERROR"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/str/index-of", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"text":"The kit parses logs: ERROR at line 12, then INFO, then ERROR again.","find":"ERROR"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"text":"The kit parses logs: ERROR at line 12, then INFO, then ERROR again.","find":"ERROR"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/str/index-of", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"text": "The kit parses logs: ERROR at line 12, then INFO, then ERROR again.",
"find": "ERROR"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "str.index_of",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_chars | 100000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |