ForHosting KIT · Data & Files

Filter CSV rows

A ten-million-row export is rarely the ten million rows you actually need — most of the time you want the subset where status equals active and region equals a specific value, and finding that subset by hand is where spreadsheets grind to a halt. This endpoint applies conditional rules to a CSV and returns only the rows that match, whatever the file's size.

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The subset problem hiding in every big export

Full exports exist because generating a filtered one for every possible use case is impractical on the source system's side, so the filtering burden lands on whoever consumes the file. A finance analyst gets every transaction ever recorded when they need only this quarter's refunds; a support team gets every ticket when they need only the ones still open and unassigned. AutoFilter in a spreadsheet handles this for a few thousand rows and starts to choke well before a file reaches the sizes real systems actually export.

How conditions are built and combined

Call POST /data/filter-csv with your file and a set of conditions — a column, an operator like equals, greater than, contains or is empty, and a value to compare against — and combine multiple conditions with AND logic, where every condition must hold, or OR logic, where any one is enough. This mirrors exactly how a WHERE clause works in SQL, so anyone who has ever written status = 'active' AND region = 'LATAM' already understands the mental model, just expressed as structured rules instead of query syntax.

Getting comparisons right on real data

Filtering only stays useful if it handles data the way it actually shows up: numeric comparisons need the column recognized as a number rather than compared as text, date ranges need actual date parsing rather than string sorting that puts "2026-1-5" after "2026-10-1", and text conditions need to tolerate case differences a human would not even notice. Getting these comparisons right is what separates a filter that quietly returns the wrong subset from one you can trust without double-checking.

Filtering as a first-class step, not an afterthought

It is tempting to treat filtering as something you do at the very end, after everything else, but doing it early in a pipeline often saves real processing cost downstream — there is no reason to transform, merge or deduplicate rows you are going to discard anyway. Treating filter as its own composable step means you decide where in the pipeline it makes sense to narrow the dataset, rather than always filtering last out of habit.

Where it sits in automation

The task runs asynchronously and returns a task_id immediately, so it fits naturally before a merge, after a transform, or as a standalone step in a scheduled job that extracts today's relevant rows from an ever-growing export. Results come back by signed webhook or a 24-hour signed link, ready to feed straight into a report, an alert, or the next stage of the pipeline.

What you can do with it

Isolating open support tickets

Filter a full ticket export down to only status = open and priority = high, so a team dashboard shows exactly what needs attention today.

Regional or segment reporting

Pull only the rows for a specific region or customer segment from a company-wide export before building a localized report.

Data quality pre-check

Filter for rows where a required field is empty or a value falls outside an expected range, isolating records that need cleanup before import.

Time-bounded extracts

Extract only transactions or events within a date range from a full historical export, without loading the whole file into a database first.

FAQ

Can I combine multiple conditions when filtering a CSV?

Yes, this filter csv rows api supports AND logic, where every condition must match, and OR logic, where any single condition is enough.

What comparison operators are supported?

Equals, not equals, greater than, less than, contains, starts with, and is empty are supported, applied with correct numeric and date handling, not plain text comparison.

Does filtering handle dates and numbers correctly, not just text?

Yes, columns recognized as numbers or dates are compared as such, so a range filter on dates or amounts behaves correctly instead of sorting them as strings.

Is there a free tier to try the filter endpoint?

The tool above runs free in your browser. The API is paid — each call draws from your prepaid ForHosting KIT balance: top up from $10.00 (it never expires), pay each request's published price, and a call with no balance returns HTTP 402. No subscription, no tokens, and a failed task is never charged.

How large a CSV file can I filter?

Submit large files as async requests; each returns its own task_id, so filtering runs in the background regardless of file size without blocking your pipeline.

What happens to rows that do not match my conditions?

They are excluded from the output entirely; the response contains only rows that satisfy your filter conditions.

How do I receive the filtered CSV?

Through a signed webhook, recommended for automated workflows, or a signed link valid for 24 hours if you prefer manual retrieval.

How much does the CSV filter API cost?

$0.002 per request, charged only when the filtering task completes successfully.

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

POSThttps://api.kit.forhosting.com/data/filter-csv

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, and soon from our app, email and Telegram.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/data/filter-csv \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d &#39;{"text":"…"}'

const res = await fetch("https://api.kit.forhosting.com/data/filter-csv", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "text": "…"
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/data/filter-csv",
    headers={"Authorization": f"Bearer {os.environ[&#39;KIT_KEY']}"},
    json={
    "text": "…"
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/data/filter-csv", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => &#39;{"text":"…"}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"text":"…"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/data/filter-csv", 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": "…"
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "data.filter_csv",
  "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

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Limits

max_mb 25

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.

Read the full KIT documentation →

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