# Compare Sizes

> A free tool for comparing the physical size of objects. Enter two or more sets of
> dimensions and they are drawn together to scale in a 3D viewer, so the difference
> can be seen rather than worked out. Sizes can be entered in inches, feet,
> centimetres, millimetres or metres, and every comparison can be saved and shared
> at its own permanent URL.

Compare Sizes has been running since 2016 and holds roughly 45,417 saved
comparisons covering consumer electronics, PC cases and components, furniture,
vehicles, animals, sports equipment and astronomical bodies.

## How the site is organised

- Every saved comparison lives at `/comparison/<slug>/<id>`, for example
  https://comparesizes.com/comparison/PC-Case-Sizes-size-comparison/1516039620870
- Each comparison page states the objects compared, their dimensions in the units
  the author entered, and the same dimensions converted to both centimetres and
  inches.
- The 3D viewer needs JavaScript, but the dimensions, the object names and the
  comparison itself are in the server-rendered HTML and need no scripting to read.

## Making a comparison by writing a URL

You do not need to call an API or save anything to show someone a size comparison.
Put the objects in the query string and the page draws them:

    https://comparesizes.com/compare?item=Desk:120x60x75cm&item=Office chair:45x45x90cm

Repeat `item` once per object. Each one is `Name:dimensions`, or just `Name` to look
it up in the site's catalogue of user-contributed objects:

    https://comparesizes.com/compare?item=Boeing 747&item=Blue whale&item=School bus

- Dimensions are three numbers separated by `x` (`×`, `*`, `,` and `by` also work),
  with an optional unit: `mm cm m km in ft yd mi um nm`, plus `"` and `'`. A single
  number is read as a cube. `unit=` sets a default for items that name no unit; it
  is `cm` otherwise.
- The largest of the three numbers is stood up as the height, which is usually what
  was meant. `autoflip=0` keeps the order as written.
- `items=A:...;B:...` is the same thing in one parameter, if that is easier.
- Up to 12 objects. Names the catalogue does not recognise are dropped and the page
  says which, so pass dimensions when you know them — the catalogue is
  user-contributed and a loose name match may not be the object you meant.
- The page carries an `og:image`, so the link unfurls into a picture of the
  comparison when it is pasted into a chat. That card is also fetchable on its own
  at `/og/compare.png?item=...`, 1200x630 PNG, same parameters.
- These pages are `noindex` and nothing is stored. A visitor can press Save to turn
  one into a permanent `/comparison/<slug>/<id>` page.

Full description: https://comparesizes.com/url-api — and as OpenAPI: https://comparesizes.com/openapi.yaml

## Key pages

- [Compare Sizes](https://comparesizes.com/): the tool itself, plus recently added and popular comparisons
- [Build a comparison from a URL](https://comparesizes.com/url-api): the URL scheme above, in full
- [OpenAPI description](https://comparesizes.com/openapi.yaml): the same thing for tooling
- [Privacy policy](https://comparesizes.com/privacy.php): what the site stores and which third parties are involved
- [Sitemap](https://comparesizes.com/sitemap.xml): every indexable comparison

## Popular comparisons

- [PC Case Sizes size comparison](https://comparesizes.com/comparison/PC-Case-Sizes-size-comparison/1516039620870): 5 objects compared to scale
- [Box size comparison](https://comparesizes.com/comparison/Box-size-comparison/1542984180237): 2 objects compared to scale
- [3D Laptop Comparison size comparison](https://comparesizes.com/comparison/3D-Laptop-Comparison-size-comparison/1549625332242): 4 objects compared to scale
- [Gpu compare](https://comparesizes.com/comparison/Gpu-compare-size-comparison/1575224670224): 2 objects compared to scale
- [PS5 (disc) vs PS5 (digital) vs PS5 Slim (disc) vs PS5 Slim (digital)…](https://comparesizes.com/comparison/PS5-disc-vs-PS5-digital-vs-PS5-Slim-disc-vs-PS5-Slim-digital-size/1717973113309): 4 objects compared to scale
- [NCASE M1 V6 vs Cooler Master NR200P vs Lian Li TU150 size comparison](https://comparesizes.com/comparison/NCASE-M1-V6-vs-Cooler-Master-NR200P-vs-Lian-Li-TU150-size-comparison/1592771826490): 3 objects compared to scale
- [CH160 vs CH160 PLUS vs CH260 size comparison](https://comparesizes.com/comparison/CH160-vs-CH160-PLUS-vs-CH260-size-comparison/1754312494253): 3 objects compared to scale
- [Ipad 12.9 vs A4 Paper vs Ipad pro 11 vs iphone 13 pro max size compa…](https://comparesizes.com/comparison/Ipad-129-vs-A4-Paper-vs-Ipad-pro-11-vs-iphone-13-pro-max-size-comparison/1648991436401): 4 objects compared to scale
- [Lian/Dan a3 mATX vs Nr200 vs Lain Li Q58 vs Dan a4 H2O size comparison](https://comparesizes.com/comparison/LianDan-a3-mATX-vs-Nr200-vs-Lain-Li-Q58-vs-Dan-a4-H2O-size-comparison/1657300626743): 4 objects compared to scale
- [Dan A4 vs FormD T1 vs LL Dan A4 h2o vs Phanteks Evolv Shift XT (MINI…](https://comparesizes.com/comparison/Dan-A4-vs-FormD-T1-vs-LL-Dan-A4-h2o-vs-Phanteks-Evolv-Shift-XT-MINI-vs/1650220035401): 12 objects compared to scale
- [NZXT H210 vs CM NR200 size comparison](https://comparesizes.com/comparison/NZXT-H210-vs-CM-NR200-size-comparison/1595350297801): 2 objects compared to scale
- [Human vs Dragon size comparison](https://comparesizes.com/comparison/Human-vs-Dragon-size-comparison/1705178844391): 2 objects compared to scale
- [Lian Li O11Dynamic XL vs Lian Li O11 Dynamic size comparison](https://comparesizes.com/comparison/Lian-Li-O11Dynamic-XL-vs-Lian-Li-O11-Dynamic-size-comparison/1592229893145): 2 objects compared to scale
- [NCASE vs NR200 size comparison](https://comparesizes.com/comparison/NCASE-vs-NR200-size-comparison/1594347873374): 2 objects compared to scale
- [SSUPD Meshlicious vs Louqe Ghost S1 vs Ncase M1 vs NR200 size compar…](https://comparesizes.com/comparison/SSUPD-Meshlicious-vs-Louqe-Ghost-S1-vs-Ncase-M1-vs-NR200-size/1614714840792): 4 objects compared to scale
- [Lian Li O11Dynamic XL vs Lian Li O11 Dynamic vs mini size comparison](https://comparesizes.com/comparison/Lian-Li-O11Dynamic-XL-vs-Lian-Li-O11-Dynamic-vs-mini-size-comparison/1605829768184): 3 objects compared to scale
- [PS5 Redesign specs vs PS5 Digital Redesign specs vs PS5 Original spe…](https://comparesizes.com/comparison/PS5-Redesign-specs-vs-PS5-Digital-Redesign-specs-vs-PS5-Original-specs/1696956384858): 6 objects compared to scale
- [Rtx 3080 vs rtx 3090 vs gtx 1070 size comparison](https://comparesizes.com/comparison/Rtx-3080-vs-rtx-3090-vs-gtx-1070-size-comparison/1598982899873): 3 objects compared to scale
- [SFF PC Cases size comparison](https://comparesizes.com/comparison/SFF-PC-Cases-size-comparison/1553030728627): 4 objects compared to scale
- [Mini ITX Cases size comparison](https://comparesizes.com/comparison/Mini-ITX-Cases-size-comparison/1562761955438): 6 objects compared to scale
- [NZXT H510 vs NZXT H210 size comparison](https://comparesizes.com/comparison/NZXT-H510-vs-NZXT-H210-size-comparison/1592764844582): 2 objects compared to scale
- [JONSBO D31 vs ASUS Prime AP201 vs JONSBO D30 vs Cooler Master Master…](https://comparesizes.com/comparison/JONSBO-D31-vs-ASUS-Prime-AP201-vs-JONSBO-D30-vs-Cooler-Master-MasterBox/1679078878017): 8 objects compared to scale
- [NCASE M1 vs DAN C4 SFX vs NR200 vs Meshlicious size comparison](https://comparesizes.com/comparison/NCASE-M1-vs-DAN-C4-SFX-vs-NR200-vs-Meshlicious-size-comparison/1623770532215): 4 objects compared to scale
- [Mousepad size comparison](https://comparesizes.com/comparison/Mousepad-size-comparison/1563698470779): 2 objects compared to scale
- [Ghost S1 vs Dan A4 vs FormD T1 vs IQUNIX ZX-1 Air vs IQUNIX ZX-1 Wat…](https://comparesizes.com/comparison/Ghost-S1-vs-Dan-A4-vs-FormD-T1-vs-IQUNIX-ZX1-Air-vs-IQUNIX-ZX1-Water-vs/1602669850213): 8 objects compared to scale

## Notes for automated readers

- Dimensions in the page text are written height x width x depth.
- Comparisons created by visitors are user-generated. Dimensions are as entered by
  whoever made the comparison and are not verified by the site.
- Endpoints under `/load.php`, `/save.php`, `/saveImage.php`, `/sizeSearch.php` and
  `/searchSavedItems.php` are application calls, not documents; robots.txt asks
  crawlers to skip them.
- Contact: comparesizessite@gmail.com