**28 Free Nature Identification Tools — Keys, Charts & Calculators**

> Free browser tools for identifying what you found outside: 28 filterable keys and field calculators covering 749 catalogued entries. No account, nothing to install.

Source: https://orvik.app/tools/

Free tools

# 28 field tools for working out what you just found

Every one of them runs in this browser, on this page, with nothing to install and no
account to make. Most are **determination keys**: you tell the tool what you
can actually see — the number of toes in the print, the streak the rock leaves on a tile,
how many petals the flower has — and it narrows 749 catalogued entries down to the
handful that fit.

Tools **28** Catalogued entries **749** Sign-up **None** Price **Free**

## Plants & trees

7 tools

- [Is this plant poisonous to dogs or cats? Look up 73 plants and see what each one does to a dog, a cat or a horse.](https://orvik.app/tools/plant-toxicity-checker/)
- [Identify a tree by its leaf Arrangement, compound or simple, margin and shape — 43 trees, four questions.](https://orvik.app/tools/leaf-identifier/)
- [Identify a tree by its bark Texture, colour and pattern — identify 34 trees with no leaves on them.](https://orvik.app/tools/tree-bark-identifier/)
- [What wildflower is this? Petal count, arrangement and habitat narrow 30 wildflowers.](https://orvik.app/tools/wildflower-identifier/)
- [What succulent is this? Growth form, leaf shape and flower narrow 28 succulents.](https://orvik.app/tools/succulent-identifier/)
- [How old is this tree? Wrap a tape round the trunk and get the age the way an arborist does.](https://orvik.app/tools/tree-age-calculator/)
- [When do I start these seeds? One frost date turns into a sowing and transplant calendar for 34 crops.](https://orvik.app/tools/seed-starting-calculator/)

## Insects & spiders

4 tools

- [What caterpillar is this? Colour, hair, size and host plant narrow 34 caterpillars down in seconds.](https://orvik.app/tools/caterpillar-identifier/)
- [What spider is this? Markings, web shape and size narrow 31 common spiders down fast.](https://orvik.app/tools/spider-identifier/)
- [What beetle is this? Shape, colour, size and habitat narrow 28 beetles, pests flagged.](https://orvik.app/tools/beetle-identifier/)
- [Is that a butterfly or a moth, and which one? Colour, wingspan and flight time narrow 28 butterflies and moths.](https://orvik.app/tools/butterfly-moth-identifier/)

## Animals

4 tools

- [What animal made this track? Count toes, check for claws, measure the print — narrows 36 species fast.](https://orvik.app/tools/animal-track-identifier/)
- [Whose droppings are these? Shape, size, contents and location narrow 30 animals down to a shortlist.](https://orvik.app/tools/animal-scat-identifier/)
- [What snake did I just see? Pattern, size and region — 28 US snakes, venomous ones flagged.](https://orvik.app/tools/snake-identifier/)
- [How old is my dog or cat in human years? The veterinary life-stage curve, scaled by adult size. Not times seven.](https://orvik.app/tools/pet-age-calculator/)

## Birds

2 tools

- [Whose egg is this? Colour, markings, size and nest site narrow 34 birds by their eggs.](https://orvik.app/tools/bird-egg-identifier/)
- [Which bird did this feather come from? Size, pattern and shape narrow 26 birds from a single feather.](https://orvik.app/tools/feather-identifier/)

## Rocks & minerals

5 tools

- [What kind of rock is this? Grain size, layering and three kitchen tests narrow 33 common rocks.](https://orvik.app/tools/rock-identifier/)
- [Which mineral is this? Streak, lustre, hardness and cleavage — the real determinative key, for 36 minerals.](https://orvik.app/tools/mineral-identifier/)
- [What gemstone is this? Colour, hardness and optical effect — 27 gems, with the fakes named.](https://orvik.app/tools/gemstone-identifier/)
- [What fossil is this? Shape, size and host rock narrow 26 common fossils.](https://orvik.app/tools/fossil-identifier/)
- [Mohs hardness scale, with a scratch test you can actually do What scratches what, and which household object sits at each step.](https://orvik.app/tools/mohs-hardness-scale/)

## Food & foraging

2 tools

- [What berry is this, and can you eat it? Colour, growth habit and habitat — 30 wild berries, toxic ones flagged.](https://orvik.app/tools/wild-berry-identifier/)
- [What mushroom is this? Cap, underside, spore print and substrate — 28 fungi, deadly ones flagged.](https://orvik.app/tools/mushroom-identifier/)

## Sky, coast & ground

2 tools

- [What cloud is that? Height, shape and cover name 29 cloud types — and what each one forecasts.](https://orvik.app/tools/cloud-identifier/)
- [What shell did I find on the beach? Shape, size and which coast — 29 shells people actually pick up.](https://orvik.app/tools/seashell-identifier/)

## Collecting

2 tools

- [What kind of arrowhead did I find? Outline, notching and size place 28 North American point types.](https://orvik.app/tools/arrowhead-identifier/)
- [What is the silver in this coin worth? Melt value for 22 circulating silver and gold coins at any spot price.](https://orvik.app/tools/coin-melt-value-calculator/)

## Why a filter beats a wall of photographs

Search "caterpillar identification chart" and you get a page of photographs with names
under them. That works if your caterpillar happens to be one of the first dozen shown, and
fails completely otherwise, because scanning pictures is a linear search through a space
that is not organised the way your observation is. You know the thing was green, about four
centimetres, and had a horn on its rear end. A photo grid makes you check that against
sixty pictures one at a time.

A key inverts it. You state what you observed, and everything that contradicts the
observation disappears. Three well-chosen filters usually cut a list of forty candidates to
two or three, and at that point the remaining work is comparing your specimen against a
short, specific description rather than against a mood board.

That is the whole design principle of this section. Each tool asks only for features
**a person without equipment can genuinely observe** — colour, count, shape,
size against a coin, the substrate it was found on — and never for characters that require a
microscope, a spore print left overnight, or a key you would need training to read.

## Everything renders before the JavaScript does

The filters are JavaScript, but the data is not. Every entry in every key is written into
the page as plain HTML: names, scientific names, sizes, ranges, the diagnostic sentence and
the look-alike warning. Turn scripting off and you lose the ability to narrow the list, and
nothing else. That matters for three groups of readers — people on locked-down networks,
people using a screen reader that gets confused by dynamic filtering, and the search and
language-model crawlers that do not execute scripts and would otherwise see an empty
page.

It also means you can use a key with no signal. Load the page while you still have
reception, and the whole catalogue is already in your phone.

## Where the entries come from, and where the limits are

Each tool lists its sources at the bottom of its own page, and they are the obvious
authorities for the subject: the ASPCA toxic plant database, USDA and Forest Service field
keys, state extension services, the Mohs scale and standard determinative mineralogy, the
World Meteorological Organization cloud atlas, regional natural history museums. Where two
sources disagree, the more conservative reading wins — a key that under-warns is worse than
one that over-warns.

Three limits are worth stating in the same breath. These keys cover **common
species in North America and Europe**, and they say so; a key with forty entries
cannot represent a continent with four hundred candidates, so a specimen that matches
nothing is more likely to be outside the catalogue than to be exotic. Several groups —
fungi, wild berries, spiders, snakes — carry a safety banner because a wrong identification
there has consequences that a wrong maple does not, and in those groups the tool is designed
to produce a shortlist for an expert rather than a verdict. And where an entry mentions a
risk to a person or an animal, the correct next step is a poison centre or a doctor, not a
web page.

## How to get a usable answer in about a minute

1. **Measure something.** Almost every key has a size filter, and size is the single most discriminating character available to somebody without a hand lens. Put a coin, a car key or your thumb next to the specimen before you photograph it.
2. **Start with the filter you are most certain about**, not the one at the top. If you are sure about the number of toes and unsure about the colour, set the toes first and look at what survives.
3. **Stop filtering when the list gets to five.** Reading five short descriptions is faster and much more reliable than adding a fourth filter you are guessing at, and guessed filters are how you eliminate the right answer.
4. **Read the "confused with" line.** It is there because the most common identification error in each group is a specific one, and knowing which pair you are choosing between is most of the work.
5. **If nothing matches, remove a filter rather than adding one.** An empty result almost always means one observation was wrong, not that you have found something undescribed.

## Which tool answers which question

The catalogue divides into two kinds of thing, and it is worth knowing which
you need before you open one.

A **determination key** takes an observation and returns a shortlist. You
tell it that the print had four toes and claw marks and was six centimetres long, and it
removes everything that contradicts you. Keys work on things that exist in discrete kinds —
species, minerals, cloud genera, point types — and they are the right tool when the question
is "what is this".

A **calculator** takes a measurement and returns a number. Trunk
circumference to tree age, a frost date to a sowing calendar, spot price to melt value.
Calculators work on continuous quantities and they are the right tool when the question is
"how much" or "when". They also carry their assumptions in the open: the tree age tool
prints its error bars, and the coin tool asks you for the spot price rather than fetching a
number nobody will check.

Several subjects appear in both forms, deliberately. The rock key names a rock; the Mohs
scale tells you what the scratch test you just did actually means. The plant toxicity
checker names a species; the seed calendar tells you when to sow one.

## The safety flags are not boilerplate

Five of these tools carry a red banner at the top, and each one is there because a wrong
answer in that subject has a consequence a wrong maple does not.

- **Mushrooms.** The death cap and destroying angel cause around 90 % of fatal mushroom poisonings worldwide, they look like ordinary field mushrooms, and the illness appears to resolve on day two before the liver fails on day three. That tool is built to produce a shortlist for an expert and it never authorises eating anything.
- **Wild berries.** Colour rules do not work — there are excellent red berries and lethal black ones — and the toxins that matter give no warning taste.
- **Snakes.** Most bites happen to people who were handling, killing or moving the animal. The tool is designed to be used from several metres away.
- **Caterpillars.** Roughly two dozen North American species sting, and the ones that look softest — the puss caterpillar in particular — are the worst.
- **Plants around pets.** The severity column exists because "toxic" is applied identically to a sore mouth and to kidney failure in eighteen hours.

Where an entry names a risk to a person or an animal, the correct next step is a poison
centre, a vet or a doctor. In the United States that is (800) 222-1222 for people and
(888) 426-4435 for animals; in the UK, 111 and your own vet. A web page is a good place
to find out what something is and a bad place to decide what to do about it.

## Nothing here sends your input anywhere

Every filter, every calculation and every search box on this site runs in your browser on
your device. There is no server call when you tick a box, nothing is logged about what you
filtered, and no result is transmitted. That is a consequence of how the tools are built
rather than a policy statement: the data is already in the page, and filtering it is a few
lines of JavaScript operating on the DOM.

Two practical benefits follow. The tools work with no signal once the page has loaded, so
a key opened at the trailhead still works in the valley. And they keep working if this site
ever stops being maintained, because a saved page is a complete copy of the tool.

## What the paid apps charge

The other half of this question is what the identification apps in the store cost, and it
is harder to find out than it should be: Apple lists in-app purchase names and prices but not
the billing period, so a low tier is frequently weekly rather than one-off.

We publish [the whole table](https://orvik.app/compare/) — every in-app purchase tier for the
major identification apps, read from the App Store and dated — because the single most useful
fact in that market is which apps have **nothing inside them to buy at all**. The
answer turns out to correlate almost perfectly with who publishes them: the free ones come
from universities, public research institutes and non-profits.

## What the app adds

A key needs you to describe the thing. Orvik does the opposite: it reads the photograph
and proposes the species, then shows the near-misses so you can check the reasoning rather
than take the answer on faith. The two work well in sequence — photograph it in the app to
get a name, then bring the name back to the relevant key here and confirm it against the
diagnostic features. An identification that survives both is one you can act on.

Everything on this page stays free and stays in the browser regardless. The tools are not
a trial, they do not ask for an email, and none of them sends your input anywhere: the
filtering happens on your device, which is why they keep working when the signal does
not.

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