Brachiosaurus Size Comparison
The Brachiosaurus 3D Viewer shows a tall sauropod at published figures: length about 22 m, head height about 9.4 m, weight about 46.9 tonnes. Turn on Size vs human and a 1.8 m person appears at the true length ratio, so the giraffe-like scale gap is readable at a glance.
Brachiosaurus published figures
These figures follow the Natural History Museum Dino Directory listing for Brachiosaurus:
| Measure | Figure | Vs a 1.8 m person |
|---|---|---|
| Length | 22.0 m (NHM) | ~12x a person end-to-end at the 22 m figure |
| Head height | about 9.4 m (common reconstructions; model scale) | ~5.2x adult standing height; the model uses this for Size vs human |
| Weight | 46900 kg / about 46.9 tonnes (NHM) | about 46.9 metric tons on the facts panel |
| When it lived | 152-145 million years ago | Late Jurassic; herbivore; named by Elmer S. Riggs, 1903, Colorado (B. altithorax) |
What the on-screen facts panel shows next to this table
The facts panel beside the Brachiosaurus canvas is shorter than the table above, and it carries five rows: Length 22 m, Weight 46.9 t, When it lived 152-145 Mya (Late Jurassic), Diet Herbivore, and Described - named by Riggs, 1903 (B. altithorax), Colorado. There is no head-height row in the panel, so the about 9.4 m figure lives here in the table instead. Below the rows the panel adds the shape note: longer front legs than hind legs lifted the chest and neck high, which is the giraffe-like silhouette of a high browser, and soft tissue and color are unknown. It closes by naming the model as an artistic reconstruction and crediting its author, because fossils do not preserve skin or color.
How the Brachiosaurus size-vs-human toggle stays honest
The Brachiosaurus model is normalised to a fixed on-screen length so that any species fits the canvas the same way. Size vs human then scales the 1.8 m figure by the same units-per-metre factor derived from the 22 m length, which is why the person ends up at the true ratio rather than at a guessed one. The figure stands off to the side of a sauropod rather than under it, so the neck and the person stay visible together. Tap Size vs human under the canvas to show the figure, and the button flips to Hide human to put it away. The comparison is proportional, not a decorative sticker.
What a person would see beside a Brachiosaurus
What a person would see is a head towering many times above their own: at about 9.4 m head height, a Brachiosaurus head sits far above a 1.8 m person, and the taller forelimbs give the giraffe-like silhouette. From snout to tail tip the animal spans about 22 m, roughly twelve people laid end to end. Turn on the person in the viewer and orbit beside a foreleg to feel how the high-browsing neck towers past the scale figure.
The four Brachiosaurus controls under the canvas
Open the Brachiosaurus 3D Viewer and the status line reports its own progress. It first says it is preparing the scene, then that the 3D engine is loading, about 0.7 MB, one time and then cached; once the scene is live it switches to drag to rotate, scroll or pinch to zoom, click a body part for a fact. Drag with the pointer to orbit, and use the scroll wheel or a two-finger pinch to zoom. Four controls sit under the canvas:
- Fullscreen - expands the wrapper around the scene, so the buttons stay visible instead of disappearing with the page
- Stop rotation / Auto-rotate - freezes the auto-spin, then resumes it
- Idle motion / Stand still - adds subtle breathing and leg sway, then holds the pose
- Size vs human / Hide human - shows or hides the 1.8 m scale figure described above
Part inspection is a short click rather than a drag: the viewer only treats a press as a click when the pointer travelled under about 8 pixels, so an orbit never fires a part note by accident. Clicking the head, the neck, the body, a leg, or the tail swaps the panel for a note on that part, and clicking empty space returns to the fact sheet. The neck note is a good example of the tone: vertebra count and length come from the fossil, while posture is still debated between studies.
The in-browser viewer against phone AR apps and museums
These rows compare what the Brachiosaurus viewer actually ships against typical phone AR apps, a museum hall visit, and a still photo:
| Aspect | In-browser 3D viewer | Phone AR app | Museum / static image |
|---|---|---|---|
| Install / download | 0 MB app install; three.js is vendored and cached after first load | Often 50 to 500 MB store download | Travel time; or 0 MB for a photo |
| Time to first view | Seconds - one page load; the engine lazy-loads after paint | Minutes - install, permissions, tracking setup | Hours for a visit; instant for a photo |
| Place in a physical room | No - orbit on a flat screen only | Yes - true AR placement when tracking works | Hall scale in person; none in a photo |
| Desktop without a phone | Yes - current browser with WebGL | Usually no | Photo yes; museum no |
| Published size figures on hand | Yes - 22.0 m length (NHM), head about 9.4 m, about 46.9 t / 46900 kg, 152-145 Mya | Varies by app | Labels vary; a photo rarely carries the full sheet |
| Reconstruction honesty | Artistic skin and color on a real published model; NHM Brachiosaurus listing, not a Giraffatitan mount or a movie design | Often sells one settled movie silhouette | Bones are real; color still interpretive |
Two details behind the first two rows are worth knowing. The engine is fetched after the page paints rather than before, so the layout and the numbers are readable while the 3D scene is still arriving, and the browser keeps it cached for later visits. A first-paint procedural shape of the animal is drawn immediately, then a real published model, about 0.6 MB and released under CC0 by gabi123 via Printables, replaces it when available; the status line changes to say it is showing a real 3D model of this species, and the panel credits the author. If a device cannot start WebGL the scene does not draw, and the status line says so plainly while the facts panel keeps working, so the measurements are never locked behind the graphics.
Everything runs on your device, so there is no account and nothing about the visit is sent to a server - which is what makes it usable on a locked-down classroom laptop. Pick a phone AR app instead when you need the silhouette standing on your own floor, since this viewer never claims room placement. A museum wins for walking beside mounted sauropod bone at hall scale, where the height of a raised Brachiosaurus neck is easiest to feel. A static image wins only when you need one shareable frame with no interactivity.
What the Brachiosaurus size numbers are not
These are published bone-based estimates, not precision measurements of one animal, and sources do not agree on every value. Skin and color are an artistic reconstruction, and African Tendaguru material once labelled Brachiosaurus is now usually placed in the related genus Giraffatitan - the figures here follow the NHM Brachiosaurus listing, so this page does not treat Giraffatitan mounts as Brachiosaurus. The viewer is a screen-based model: it does not place the animal in your room, does not claim soft-tissue accuracy, does not invent game score or win states, and is not a ranking of commercial AR brands.
Other dinosaurs to compare
Other dinosaurs in the collection make useful size comparisons too: Brachiosaurus is one of the tallest sauropods here, so for a horned quadruped herbivore closer to the ground, see the Triceratops 3D Viewer, or for a marine reptile of similar overall length, see the Mosasaurus 3D Viewer.
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