Docs/APIs/File Size Formatter

File Size Formatter

Convert bytes to human-readable file sizes

OperationalCredits 1 per callp50 150msData ConversionStar

Overview

File Size Formatter works by dividing byte values by the appropriate divisor (1024 for binary, 1000 for decimal) to calculate sizes in various units. Automatically selects the most appropriate unit or allows manual specification.

Endpoint

One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.

GEThttps://api.apiverve.com/v1/filesizeformatter
curl "https://api.apiverve.com/v1/filesizeformatter?bytes=1073741824&unit=GB&precision=2&standard=binary" \
  -H "x-api-key: your_api_key_here"
const res = await fetch('https://api.apiverve.com/v1/filesizeformatter?bytes=1073741824&unit=GB&precision=2&standard=binary', {
  headers: { 'x-api-key': 'your_api_key_here' },
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);

const { data } = await res.json();
console.log(data);
import requests

res = requests.get(
    "https://api.apiverve.com/v1/filesizeformatter?bytes=1073741824&unit=GB&precision=2&standard=binary",
    headers={"x-api-key": "your_api_key_here"},
    timeout=15,
)
res.raise_for_status()

print(res.json()["data"])
package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/filesizeformatter?bytes=1073741824&unit=GB&precision=2&standard=binary", nil)
	req.Header.Set("x-api-key", "your_api_key_here")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	out, _ := io.ReadAll(res.Body)
	fmt.Println(string(out))
}

Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.

Authentication

Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Parameters

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.

ParameterTypeDescription
bytesRequiredintegerNumber of bytes to format
range 0–∞
unitOptionalstringSpecific target unit (optional, auto-selects best unit if not specified)
autoBKBMBGBTBPBEB+2
precisionOptionalintegerDecimal places (0-10)
default 2 · range 0–10
standardOptionalstringStandard to use: binary (1024) or decimal (1000)
binarydecimal
default binary

Response

Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.

Sample response
{
  "status": "ok",
  "error": null,
  "data": {
    "bytes": 1073741824,
    "formatted": "1 GiB",
    "value": 1,
    "unit": "GiB",
    "standard": "binary",
    "precision": 2,
    "conversions": {
      "B": 1073741824,
      "KiB": 1048576,
      "MiB": 1024,
      "GiB": 1,
      "TiB": 0,
      "PiB": 0,
      "EiB": 0,
      "ZiB": 0,
      "YiB": 0
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

FieldTypeExampleDescription
bytesnumber1073741824Original byte value in numeric format
formattedstring"1 GiB"Formatted file size with unit as human-readable string
valuenumber1Numeric value in the selected or auto-determined unit
unitstring"GiB"File size unit used in the conversion (e.g., GiB, MB)
standardstring"binary"Standard used for conversion: binary or decimal
precisionnumber2Decimal places applied to the formatted value
conversionsPremiumobject{...}Complete conversion table with values across all units
BPremiumnumber1073741824The size expressed in bytes
KiBPremiumnumber1048576The size expressed in kibibytes (1024 bytes)
MiBPremiumnumber1024The size expressed in mebibytes
GiBPremiumnumber1The size expressed in gibibytes
TiBPremiumnumber0The size expressed in tebibytes
PiBPremiumnumber0The size expressed in pebibytes
EiBPremiumnumber0The size expressed in exbibytes
ZiBPremiumnumber0The size expressed in zebibytes
YiBPremiumnumber0The size expressed in yobibytes

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.

StatusMeaningWhat to do
400Input was rejectedRead error; it names the parameter.
401Key missing or invalidCheck the header name and the key value.
403Key valid, but not permittedA key restriction or IP allow-list; see key scoping.
429Rate limited, or out of creditsRead error to tell them apart; see rate limits.

Use cases

File Management
Display file sizes in user-friendly formats in file managers and storage applications
Storage Analytics
Format storage usage data in dashboards and analytics reports
Data Transfer
Show download and upload sizes in appropriate units during file transfers
API Responses
Convert byte sizes to readable formats in API responses and data exports

Other ways to use File Size Formatter

Set up File Size Formatter on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.VerveKitReference →
Use it in Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheetsReference →
Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContextReference →

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