API · /dpi-api

DPI & Print Size API

healthy 3,639 Subscribers

Resolution, print-size and pixel-density maths for print, design, photography and screens. The resolve endpoint takes any two of pixels, DPI and physical length and computes the third, returning the size in inches, centimetres, millimetres and points — so you can answer "how big will a 3000-pixel image print at 300 DPI" or "what DPI do I get printing 3000 px at 10 inches". The ppi endpoint computes a screen's pixel density from its resolution and diagonal size, plus the dot pitch in millimetres, the total megapixels and the aspect ratio. The convert endpoint converts a length between pixels, inches, centimetres, millimetres and points (PostScript points, 1/72 inch), using a DPI when pixels are involved. Everything is computed locally and deterministically, so it is instant and private. Ideal for print and prepress, graphic and web design, photography, and screen and display specs. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. This is DPI and print-size maths; for aspect ratios and resizing use an aspect-ratio API and for general unit conversion use a unit API.

#dpi #ppi #print-size #resolution #design #developer-tools

api.oanor.com/dpi-api

Get an API key Try in playground → Contact provider

Machine-readable spec so AI agents can integrate this API.

/api/dpi-api/openapi.json

/api/dpi-api/llms.txt

Discovery: GET /api/index.json lists every API.

DPI & Print Size API — live data on the oanor API marketplace

API health

healthy

Uptime: 100.00%; Server probes · 24h
Avg latency: 73 ms; Server probes · 24h
Subscribers: 3,639; active
Total calls: 80; last 7 days

Full status page → · 16 probes/24h

Pricing

Pick a tier — billed monthly, cancel anytime.

Free

6,535 calls / month
2 requests / second
Hard cap (429 above quota, no overage)
6,535 calls/month
2 req/sec
Resolve + PPI + convert
No credit card

Starter

€8.05 /month

16,050 calls / month
8 requests / second
Hard cap (429 above quota, no overage)
16.05k calls/month
8 req/sec
in / cm / mm / pt / px
Email support

Pro

€27.95 /month

211,500 calls / month
20 requests / second
Hard cap (429 above quota, no overage)
211.5k calls/month
20 req/sec
Prepress / design pipelines
Priority support

Mega

€65.95 /month

1,100,000 calls / month
50 requests / second
Hard cap (429 above quota, no overage)
1.1M calls/month
50 req/sec
Platform scale
Dedicated SLA

Built by

PremiumApi

Related APIs

Other APIs with overlapping tags.

Screen PPI API

Screen and display pixel-density maths as an API, computed locally and deterministically. The ppi endpoint computes the pixels per inch of a display from its resolution and diagonal size — along with the pixels per centimetre, the dot pitch in millimetres, the diagonal in pixels, the total pixels and megapixels, the simplified aspect ratio, and the physical width and height. The size endpoint does the inverse: from a resolution and a known PPI it works out the physical dimensions and diagonal in inches and centimetres. The retina endpoint analyses a display at a viewing distance: it computes the pixels per degree, says whether the display is effectively "retina" (pixels indistinguishable to 20/20 vision, around 60 pixels per degree), and gives the distance at which it becomes retina. Everything is computed locally and deterministically, so it is instant and private. Ideal for display and monitor tools, AV and signage planning, UI and responsive-design work, and hardware comparison sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is screen pixel density; for print resolution and image-to-print sizing use a DPI API.

api.oanor.com/ppi-api

Wallhaven API

Live wallpaper-community data from Wallhaven as an API — search the large community wallpaper collection by keyword and category (general, anime, people), sorted by favourites, views or freshness, and read any wallpaper's community engagement (favourites and views) along with its resolution, aspect ratio, file type, dominant colours and tags. The visual-community engagement layer for wallpaper, design and dashboard apps. SFW-only by design — every request is forced to safe content. Live, no key, no cache. Distinct from generic image and stock-photo APIs — this is Wallhaven's own community wallpapers, their favourites/views engagement and tags.

api.oanor.com/wallhaven-api

V&A Museum API

The Victoria and Albert Museum (V&A) collection as an API — over 1.2 million objects spanning 5,000 years of art, design and performance, from textiles, ceramics and furniture to fashion, photographs, prints and jewellery. Search and filter the collection by keyword, maker, place of origin or material/technique, optionally limited to objects that carry an image. Fetch any object by its system number for the full record: title, makers, production date, place, materials and techniques, categories and styles, gallery location and high-resolution IIIF imagery. Browse every work by a given maker (e.g. William Morris), or pull a random object. Real museum data, no key needed upstream. Ideal for art and design apps, galleries and slideshows, education and cultural research.

api.oanor.com/vam-api

Golden Ratio & Scale API

Design-proportion maths as an API, computed locally and deterministically. The divide endpoint splits a length by the golden section, the division beloved of artists and designers in which the whole is to the longer part as the longer is to the shorter, both ratios equal to φ = (1+√5)/2 ≈ 1.618 — so 100 splits into a 61.8 longer segment and a 38.2 shorter one — and can also extend a single segment to its larger or smaller golden partner. The rectangle endpoint gives the other side and the area of a golden rectangle from either side, the shape that leaves a smaller golden rectangle when you remove a square. The scale endpoint builds a modular (typographic) scale — base · ratio^step across a range of steps up and down — for harmonious type sizes and spacing, taking a numeric ratio or a named musical one such as minor-third (1.2), major-third (1.25), perfect-fourth (1.333) or golden (φ); a 16-base major-third scale gives 16, 20, 25, 31.25 and so on. Lengths are unit-agnostic. Everything is computed locally and deterministically, so it is instant and private. Ideal for graphic-design, web-design, UI, typography, layout and architecture app developers, type-scale and proportion tools, and design systems. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is proportion and scale; for pixel-density and print sizing use a PPI/DPI API.

api.oanor.com/goldenratio-api

Frequently asked questions

Quick answers about pricing, quotas, and integration.

How do I get an API key for DPI & Print Size API?

Sign up for free at oanor.com, generate an API key from the developer dashboard, and call DPI & Print Size API with the x-oanor-key header. No credit card needed for the free tier.

What's the rate limit for DPI & Print Size API?

Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.

How much does DPI & Print Size API cost?

DPI & Print Size API has a free tier with 100 calls / month. Paid plans start at €8.05 / month with higher quotas and faster rate limits.

Can I cancel my subscription anytime?

Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.

Is DPI & Print Size API GDPR-compliant?

All requests to DPI & Print Size API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.

DPI 3

Meta 1

Pick an endpoint from the list on the left to see its details and try it.

GET /v1/convert

Convert a length

Playground

Parameters

Custom headers

Language: Client:

GET /v1/ppi

Screen pixel density

Playground

Parameters

Custom headers

Language: Client:

GET /v1/resolve

Pixels / DPI / size (give any two)

Playground

Parameters

Custom headers

Language: Client:

GET /v1/meta

Spec

Playground

Custom headers

Language: Client:

Code snippets

curl https://api.oanor.com/dpi-api/SOME_PATH \
  -H "x-oanor-key: oanor_test_..."

const res = await fetch("https://api.oanor.com/dpi-api/SOME_PATH", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();

$ch = curl_init("https://api.oanor.com/dpi-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);

import requests
r = requests.get(
    "https://api.oanor.com/dpi-api/SOME_PATH",
    headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())

Ratings

No reviews yet.

Discussion

Ask questions, share usage tips, get answers from the provider and other developers. Public — anyone can read.

New thread

📌 Pinned 🔒 Locked

· ·

🔒 This thread is locked — no new replies.

No threads yet — start the discussion.

Support

Private 1:1 support with the provider — billing questions, integration issues, account problems. Only you and the provider team can see these threads.

Open new ticket

Describe what you need help with. The provider team gets an email and replies on the ticket page.

No tickets yet for this API.

Subscription active — calls can start immediately.

Send your first request —

Subscription active — copy a snippet and fire off your first call.

Pick a key

Plaintext is shown once at creation — use the prefix as a reminder.

DPI & Print Size API

API health

Pricing

Built by

Related APIs

Screen PPI API

Wallhaven API

V&A Museum API

Golden Ratio & Scale API

Frequently asked questions

Parameters

Parameters

Parameters

Code snippets

Ratings

Discussion

New thread

📌 🔒

Support

Open new ticket

Your cookie choices