TCG Grail Data Sources

This page sets out how every figure on this site is collected, how often it is refreshed, and — just as importantly — what we deliberately do not publish.

The three kinds of data we hold

Price data — public marketplace archive

Daily market and low prices in United States dollars, taken from a public archive of marketplace pricing. This is the only source of any money figure on the site, and each value is stored with the date it was collected.

Card facts — open card databases

HP, types, attacks, energy costs, retreat cost, evolution stage, rarity, regulation mark and set membership come from openly published card databases. These values are fixed properties of a printed card, so they change only when a source corrects them.

Naming and numbering — open localisation data

Card names in other languages and alternative catalogue numbering come from an openly licensed cards database. We use these to match the same card across regions, not to price it.

What is refreshed, and how often
Data area	Refreshed	Source
Market price and low price	Daily	Public marketplace price archive
Price history chart	Daily, holding up to one year of points	Public marketplace price archive
Variant prices (holofoil, reverse holofoil)	Daily, alongside the main price	Public marketplace price archive
Card facts (HP, attacks, types, evolution)	When a source publishes a correction	Open card database
Rarity and regulation mark	When a source publishes a correction	Open card database
Set details and card numbering	When a new set is added	Open card database
Card names in other languages	When a source publishes an update	Open localisation database
Card images	Once, then served from our own storage	Open card database, rehosted by us

Step 1 — Collect

Scheduled collectors read the price archive and the card databases and write the values into one data file per card.

Step 2 — Match

Cards are matched across sources by set and card number. Where a price record cannot be tied confidently to a card, we leave the price off rather than attach it to the wrong card.

Step 3 — Sanity check

A price that moves implausibly against its own recent history is held back for review instead of being published straight through.

Step 4 — Generate and publish

Pages are rebuilt from the data files. Any section whose data is missing is folded away, so a published page never shows an empty figure.

What we do not publish, and why

Several figures collectors ask about are not available to us from a free and reliably licensed source. Rather than estimate them, we leave them out entirely.

Grading population reports — no grading company publishes an open population API, so we show no population counts and no grade-by-grade values. Sealed product prices — booster boxes, bundles and packs sit behind commercial data plans we do not subscribe to. Pack pull rates — the odds of pulling a given card have never been published by the rights holder, so any figure claiming to know them is guesswork. Completed sale prices and auction results — we hold listing-derived pricing, not confirmed sold prices. Listing and transaction counts — we do not collect them.

If any of these becomes available on terms we can use, we will add it and say so here.

Reading our figures correctly

Prices here describe marketplace activity in United States dollars for a card in ordinary ungraded condition. They are a reference point, not a valuation of your particular card, whose condition, printing and grading status all move the real number.

Different sources measure prices differently, so a figure here may not match another site exactly. Our disclaimer sets out the limits in full, and our editorial policy explains how we check what we publish.

Where these figures come from, and where they can be checked

Primary official source

First-party official sources — the body that issues the data itself, such as a government agency, a statutory register or a rights holder publishing its own records.

Price figures — this site reads publicly listed marketplace prices every day and keeps them in its own dated archive, and each page states the date of the snapshot it is showing

Pokémon TCG API — open card data covering HP, attacks, types, evolution, rarity, regulation mark and set membership pokemontcg.io

Pokémon TCG Data repository — the raw card and set files published openly for that API github.com

TCGdex — openly licensed cards database covering card names in other languages and alternative catalogue numbering tcgdex.net

TCGdex cards-database repository — the files for that database, published under the MIT licence github.com

Found something wrong?

If a figure on tcggrail.com disagrees with its source, please tell us through the contact page and point us at the page and the correct value. We correct the data the page is built from, so a confirmed report fixes the problem permanently rather than for one page.