The API uses API keys, which you can manage via your customer area.
GET /api/v2/convert.php?from=hex&input=FF0000&to=ral&apikey=[YOUR_API-KEY]
Note: The key is Base64URL-encoded (URL-compatible) and secure.
GET https://qconv.com/api/v2/convert.php
| Parameters | Type | Required | Description |
|---|---|---|---|
| from | string | ✅ Yes | Source format of the color, e.g. rgb, ral or manufacturer names such as behr |
| input | string | ✅ Yes | Input value, e.g. FF0000 |
| to | string | ✅ Yes | Target format of the color, e.g. hex, cmyk or manufacturer name such as Caparol Color |
| apikey | string | ✅ Yes | Your personal and secret API key |
rgb
hex
cmyk
pantone
ral
hks
ncs
sw
All manufacturer codes that you can find on the manufacturer pages under the following link are also valid values.
https://qconv.com/en/manufactures
Look for the API code reference in the left-hand column on the manufacturer's website. Or for the following symbol:
GET /api/v2/convert.php?from=hex &input=FF0000 &to=rgb &apikey=[YOUR_API-KEY]
{
"api_version" => "v2",
"timestamp" => "2025-08-14T13:28:00+01:00",
"http_response_code" => 200,
"from": "hex",
"input": "ffa500",
"to": "rgb",
"result": "255 165 0",
"name": "Orange",
"more_conversions": {
"pantone": "185",
"ral": "3026",
"hks": "10",
"rgb": "255 0 0",
"hex": "#FF0000",
"cmyk": "0 100 100 0",
"sw": "2910",
"ncs": "S1085-Y90R"
},
"user_data": {
"username": "USER #12345",
"used tokens": 1,
"max tokens": 50,
"percentage used": "2 %"
}
}
GET /api/v2/convert.php?from=rgb &input=145, 25, 100 &to=behr &apikey=[YOUR_API-KEY]
{
"api_version" => "v2",
"timestamp" => "2025-08-14T13:28:00+01:00",
"http_response_code" => 200,
"from": "rgb",
"input": "145, 25, 100",
"to": "behr",
"result": "p120-7 glitterati",
"deltaE00": "11.2"
"match_percent": "93.1%",
"more_conversions": {
"pantone": "7649",
"ral": "4006",
"hks": "28",
"rgb": "145 25 100",
"hex": "#911964",
"cmyk": "0 83 31 43",
"sw": "6842",
"ncs": "S3055-R30B"
},
"user_data": {
"username": "USER #12345",
"used tokens": 2,
"max tokens": 50,
"percentage used": "4 %"
}
}
| Field | Type | Description |
|---|---|---|
| api_version | string | Returns the currently used version of the API, e.g. 'v2' |
| timestamp | string | Timestamp of the request in ISO 8601 format, e.g. '2025-08-14T13:42:00+01:00' |
| http_response_code | string | HTTP status code of the response (e.g. 200, 400, 500). Indicates whether the request was successful or returned an error |
| from | string | Transmitted output format |
| input | string | Transmitted original value |
| to | string | Transmitted target format |
| result | string | The converted result |
| name | string/null | Color designation for Sherwin Williams, NCS (German), HEX (if available), RGB (if available) |
| deltaE00 | string/null | Different between the colors as DeltaE2000 value (ΔE₀₀). Further explanations of Delta E 2000 or dE₀₀ can be found in the table below. |
| match_percent | string/null | Note on color matching when searching for the matching manufacturer color in percent. E.G.: 'match_percent': '92.2%', Only output when converting to manufacturer colors. |
| more_conversions | object | All other available parallel conversions as an array |
| user_data | object | Information about your API account, such as the number of conversions used. |
| error | string | If an error occurs: Object with further details such as error code, description, etc. If the request is successful, this field is zero or not present |
| ΔE₀₀ | Description | Perceptibility by humans |
|---|---|---|
| < 0.5 | Imperceptible | The color difference is not visible to the human eye. |
| 0.5 – 1.0 | Very low deviation | The color difference is only perceptible under laboratory conditions. |
| 1.0 – 2.0 | Minor deviation | The color difference is barely visible, usually acceptable. |
| 2.0 – 3.0 | Perceptible deviation | The color difference is visible in direct comparison. |
| 3.0 – 5.0 | Significant deviation | The color difference is clearly visible, possibly problematic. |
| > 5.0 | Strong deviation | As different as two different colors. |
| Further information on ΔE₀₀, Delta E 2000 or dE₀₀ can be found here: DELTA E 2000 WIKI | ||
| Status code | Meaning |
|---|---|
| 400 | Missing or invalid parameter |
| 401 | Invalid or missing API key |
| 429 | Monthly API limit reached |
| 500 | Internal server error |
If the API key is missing or an incorrect API key has been entered:
{
"api_version" => "v2",
"timestamp" => "2025-08-14T13:28:00+01:00",
"http_response_code" => 401,
"error": "Unauthorized",
}
If an entry is missing or a non-compliant value is entered:
{
"api_version" => "v2",
"timestamp" => "2025-08-14T13:28:00+01:00",
"http_response_code" => 400,
"error": "Missing input, from or to" | "Conversion failed or input invalid",
"user_data": {
"username": "USER #12345",
"used tokens": 50,
"max tokens": 50,
"percentage used": "100 %"
}
}
Each API key has a fixed monthly limit. Free are 50 tokens per month per API key. Up to two API-KEYs can be created free of charge.
This can be extended by upgrades:
With the Basic-API tariff you can create 5 API-KEYs with 200 tokens each (∑ 1.000 tokens).
With the Premium API plan, you can create 10 API-KEYs with 1.000 tokens (∑ 10,000 tokens).
With the Voyager API tariff, you can create 50 API-KEYs with 10,000 tokens each (∑ 500,000 tokens).
If you have special requirements, we can also prepare user-specific offers at any time. Please feel free to contact us.
When the limit is reached:
{
"api_version" => "v2",
"timestamp" => "2025-08-14T13:28:00+01:00",
"http_response_code" => 429,
"error": "Hello USER #12345, your monthly API quota of 50 requests has been used up. Please contact [email protected] to upgrade or wait for the next reset.",
"user_data": {
"username": "USER #12345",
"used tokens": 50,
"max tokens": 50,
"percentage used": "100 %"
}
}
Manage API keys (add/delete)
View total and API-related usage
Increase limits per month through upgrades
Generate new keys (Base64URL-safe)
Add comments for better differentiation
All parameters are sent via GET
Rate limiting per key optional
32 byte long Base64URL key
All parameters are case-insensitive
Hex code is not possible with #: Only FF0000 are valid
255,0,0 or 255 0 0 for RGB
All parameters are case-insensitive
Note: For technical reasons, it may happen that no result is output for some manufacturer names. If you need help or your conversion does not work for any other reason, please contact us at info[at]qconv.com. We offer support for customers from the 'Basic API Service'.
API-v2:
2025-08-14
API-v1:
2025-07-15