**About Orvik — Who Compiles These Keys, and How**

> Who writes Orvik's identification keys, where every number comes from, what the app can and cannot do, and how to tell us we got something wrong.

Source: https://orvik.app/about/

1. [Orvik](https://orvik.app/)
2. About

About

# Who compiles these keys, and what they are worth

**Orvik is an identification app and a reference site, run by one person
inside a small software company.** This page says who that is, where every
number on the site comes from, and — the part most sites skip — what none of it
can do for you.

Free keys **28** Entries in them **749** Articles **255** Data snapshot **2026-09-04**

## Who writes this

Orvik is published by Vast Flow, LLP, a software company, and the reference side of
it — the identification keys, the comparison pages, the open dataset — is compiled by
Merey Tleugazin, who founded it. That is the whole masthead. There is no editorial
board and no panel of consulting biologists, and inventing one would be the easiest
possible thing to do on a page like this, which is exactly why it is worth stating
plainly that there is not one.

**I am not a biologist, a mycologist, a herpetologist or a geologist.**
What I am is a person who builds software, reads primary sources carefully, and has
spent a long time on the specific problem of turning what an expert knows into
something a non-expert can actually use in a field. Every claim on this site is
either traceable to a named source, computed from a public database, or clearly
marked as a judgement — and where the answer is "an app cannot tell you this", the
page says so instead of guessing.

That framing is not modesty for its own sake. It changes what you should do with the
output. A key here narrows a list; it does not certify a specimen. If the consequence
of being wrong is a hospital visit — mushrooms, wild berries, snakes, anything a child
might have eaten — the key is a tool for describing what you are looking at to
somebody qualified, not a substitute for asking them.

## What Orvik actually is

Three things, and they work differently from each other.

**The app** reads a photograph and proposes a name, with the plausible
look-alikes listed underneath rather than hidden. It runs on iOS and Android and is
free to download. What it does is pattern recognition on an image, which means it is
good at the things that look distinctive in a photograph and unreliable at the things
that do not — and a great many identifications turn on a character a camera cannot
capture: a smell, a texture, whether the underside bruises blue, what the roots look
like. We do not publish an accuracy percentage, because a single number across every
subject would be close to meaningless: the same model that is dependable on a common
garden flower is guessing on a small brown mushroom, and one figure covering both
would mislead in the direction that matters most.

**The free browser keys** — 28 of them, holding 749
entries — are the opposite approach. Instead of a photograph, they ask you what you
can see: the shape of the web, the colour of the spore print, whether a knife scratches
it. You narrow, and the list shrinks. They need no account, they cost nothing, and
every entry is rendered into the page source, so the whole catalogue is readable even
with scripting switched off. Each entry carries the diagnostic sentence that separates
it from its nearest look-alike, because that sentence is the part that does the work.

**The reference layer** is 255 articles across 9
sections, 28 comparison and alternatives pages,
and one open dataset. The comparison pages carry no price anybody typed: every figure
comes from a dated App Store snapshot, and the build fails if a currency amount appears
in an editorial file. It is the same rule the field data lives under.

## Where the numbers come from

Every count on this site is computed at build time from a source, not written by hand,
and this is the single most load-bearing decision behind the whole thing. A number a
person types is a number that goes quietly stale: it stays on the page long after it
stopped being true, and nothing on earth notices.

For the living things in the keys, that source is
[GBIF](https://www.gbif.org/) and
[iNaturalist](https://www.inaturalist.org/):
502 entries carry a GBIF taxon key, and the 420
of those that resolve to a single species stand on 634,096,345 georeferenced
occurrence records between them, the oldest collected in 1877. Minerals get their formula, Mohs range and crystal
system from [Macrostrat](https://macrostrat.org/);
fossils get their first and last appearance from
[the Paleobiology Database](https://paleobiodb.org/).
All four are free, public and institutional, and all four are credited on every page
that uses them.

The whole snapshot is published rather than kept: it is downloadable as a single CSV
on the [open field data](https://orvik.app/data/) page under CC BY 4.0, so anybody can check
a figure here against the source, or use the join for something else entirely. Data
that cannot be checked is an assertion, and assertions are cheap.

## What this site will not tell you

A short list, because the omissions matter more than the features.

- **Whether something is safe to eat.** No key here, and no photograph fed to any app, can carry that decision. Several deadly species are close visual matches for common edible ones, and the fatal cases are usually confident people rather than careless ones.
- **Whether a bite or a rash is dangerous.** The keys flag which species are medically significant and name the poison centre. They do not diagnose, and a symptom is a reason to call somebody, not to browse.
- **What something is worth.** The collectibles keys describe what a thing is. Condition, provenance and authenticity set the price, and none of the three survives a photograph.
- **A confident answer where the evidence is thin.** Where the record is too sparse to support a claim, the tables print a dash rather than a number, and the prose says the sample is too small. That is a deliberate choice about which kind of error to make.

## How a key gets built

The order of work matters, so it is worth describing. A key starts from the question a
person actually asks, not from a taxonomy — "what spider is this" rather than
"Araneae of North America". That question sets the boundary: the entries are the things
somebody in that situation could plausibly be looking at, which is usually thirty or so,
and almost never the complete regional fauna. A key with three hundred entries is a
checklist, and a checklist does not narrow anything.

Then the filters. Each one has to be something you can observe without equipment and
without expertise: the shape of a web, the number of legs, whether the underside is
pale, how big it is against a coin. A filter that requires a hand lens or a spore print
is included only when nothing else will separate the group, and then the page says so.
The single most common failure in published keys is a character that is obvious to the
person who wrote it and invisible to everyone else.

Last comes the sentence that does the work. Every entry carries one line describing the
thing that separates it from its nearest look-alike — not a description of the species,
which any reference has, but the specific difference that resolves the specific
confusion. Where two things genuinely cannot be separated on what you can see, the entry
says that too. An honest dead end is more useful than a confident wrong turn, and it is
the point at which the correct advice is to photograph it and ask somebody.

Only then do the numbers get attached. The occurrence counts, the seasonal curves, the
hardness ranges are computed afterwards from the public databases and joined onto the
entries — they inform how a shortlist should be ordered, and they never determine what
is in it. Prior probability is genuinely useful and genuinely not identification.

## Why the keys are free, and why that is not a trick

The keys cost nothing, require no account, and carry no advertising. There is an app
behind them and the pages link to it, so the arrangement is not charity — but it is also
not the usual bargain, where a free tool is deliberately crippled until you pay. These
keys are the complete thing. Every entry renders into the page source whether or not
scripting is on, which means you can read the whole catalogue with JavaScript disabled,
save the page, or print it.

That is a deliberate decision with a cost attached: it means the keys are trivially
copyable, and some of them will be copied. The reason to do it anyway is that a
reference nobody can verify is a reference nobody should trust, and hiding the data
behind an interaction is the fastest way to make a page useless to anyone reading it
carefully — including the search engines and language models that increasingly answer
these questions on our behalf. If a model is going to summarise a page about spiders, it
ought to be summarising one where the numbers are real and the sources are named.

## When we get it wrong

With 570 automated name matches in the dataset and 749
hand-written entries in the keys, some of this is wrong. That is not false modesty; it
is arithmetic. What matters is whether it gets fixed, so: if a diagnostic character is
misleading, a range is out of date, a taxon has been resolved to the wrong species, or
a key confidently splits two things that cannot actually be split that way, write to
[support@orvik.app](mailto:support@orvik.app). Corrections go into the
next snapshot, and the date at the top of every page tells you which one you are
looking at.

The same address takes press enquiries, licensing questions about the dataset, and
anything about the app itself. It is read by the person who wrote this page.

## Start with a key rather than the app

They are free, they need no account, and they show their working.

[Browse the free tools](https://orvik.app/tools/)

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