Master Duel Tool · Free
Yu-Gi-Oh! Master Duel Deck Checker
Paste any Master Duel decklist — get main/extra/side balance, monster-spell-trap ratios, hand-brick risk from high-level monsters, and an AI report with concrete fixes.
Card data via YGOPRODeck. The AI critique is grounded only in the computed report.
What the checker examines
Master Duel decks live or die on ratios before anyone draws a card: a main deck that is consistently 40 cards instead of 45+, an extra deck that commits to real win conditions rather than five situational one-offs, a monster/spell/trap split that matches how the archetype actually wins, and above all a level distribution that does not leave you ending turns with a hand of level 7 monsters and no starters. The checker computes all of these from the names and counts you paste in — card lookups come from YGOPRODeck's live database, so newly released support is handled automatically.
Beyond raw ratios, the report bridges the two lists that matter. YGOPRODeck carries the TCG and OCG restricted lists, and Master Duel follows its own schedule — after the August 5, 2026 MD update (Harpie's Feather Storm and Lyrilusc - Independent Nightingale forbidden, Branded Fusion down to 1, Zoodiac Ratpier to 2) the lists have stayed close, but never identical. Wherever a card carries a paper-game status, the report flags it and tells you to confirm the copy limit in-game before you spend crafting points.
The AI critique is anchored to computed numbers only: no invented cards, no false "this is banned in Master Duel" claims, no pretending to know the meta tier list. It reads like an experienced duelist's first pass on your list — where the ratios are wrong, what to trim, and which direction the deck needs consistent starters versus generic interaction. Pair it with our Master Duel beginner guide for the gem economy side of deck building: crafting points, secret packs, and which events pay out.
Frequently asked questions
How do I export a decklist from Master Duel?
Master Duel does not export deck text directly — link your Konami ID on the Yu-Gi-Oh! Cards DB site or use the Master Duel Meta browser extension, then copy the deck text from the deck page. The format is simple "3 Card Name" lines with Main/Extra/Side headers, and that pastes straight in.
What does the deck report include?
Computed structure stats (main/extra/side sizes, monster-spell-trap percentages, average monster level, high-level monster share, extra-deck frame spread) plus an AI critique: consistency notes, scaling verdict, and concrete cut/add suggestions.
Does the checker use the Master Duel banlist?
Copy-limit flags come from the TCG/OCG lists that YGOPRODeck tracks — those often mirror Master Duel's list (e.g. the August 5, 2026 MD changes to Branded Fusion and Zoodiac Ratpier match OCG moves) but Master Duel has its own list. Always verify restricted copies in-game before crafting; the report hedges accordingly.
Is the deck checker free?
Yes — completely free, no account required. A light bot-protection check and a daily usage cap keep the AI report free for everyone. Card data comes from the YGOPRODeck API and is cached for a week.
Example output
Main 45, Extra 15, Side 12. Ratios: 67% monsters / 22% spells / 11% traps. Flagged: Pot of Desires ×1 (TCG: Limited). AI verdict: "Solid extender count, but extra deck runs light on link climbers."