What's New

Coins from 37 new countries + a new World Coins map 🌍
We’ve massively expanded the collection: you can now flip real circulating and historical coins from 46 countries — 321 coins in total. Explore them all on the brand-new All Fiat Coins page, which features an interactive world map (click any highlighted country to jump straight to its coins) plus a coin-or-country search. The 37 newly added currencies span every region — including the Czech Koruna, Russian Ruble, Ukrainian Hryvnia, Egyptian Pound, Kazakhstani Tenge, Brazilian Real, Venezuelan Bolívar, Philippine Piso, and Thai Baht, across Europe, the Middle East, Africa, Asia, the Americas, and Oceania. Each coin’s heads (obverse) and tails (reverse) follow the issuing central bank’s official designation, images are high-resolution where available, and full image sourcing & attribution is documented on our Acknowledgement page.

New coins: Swiss Franc 🇨🇭
You can now flip Switzerland’s coins — from the 5 Rappen up to the iconic 5 Francs featuring Helvetia. Open Select a Coin → Fiat Coins → Swiss Franc, or flip a 5 Franc coin →. All images are official Swissmint photographs in the public domain.

Multi-flip results on the site can now be independently verified — just like API flips.

Verify your multi-flip results

When you flip a coin many times on the site (any /flip-a-coin-N-times/ run), a new “Verify this flip” link appears next to “Details of the result.” It opens a permanent page showing the coin, the heads/tails counts, the timestamp, and the complete flip sequence — recorded for 30 days so anyone can confirm the outcome.

Each multi-flip is generated server-side with a cryptographically secure random source (random_bytes()), so the verification page is genuine third-party proof, not a self-reported result.

Try it: flip on flip-a-coin.com/flip-a-coin-10000-times/ and look for the “Verify this flip” link under the result.

Single flips remain instant and private (generated in your browser), so they don’t produce a verify link — the feature is for multi-flip runs.

flip-a-coin.com gained four new ways to flip a coin from outside the website. If you use ChatGPT, Claude, or build with any AI / HTTP-capable tool, please try them out.

1. The public API is live — use it from anything

A free, unauthenticated JSON API can flip up to 100,000 fair coins per call. Just GET https://flip-a-coin.com/api/flip. Pass heads/tails for custom labels, n for multi-flip, format=binary for compact output. Every flip is generated with a server-side CSPRNG. No API key, CORS enabled, 60 req/min and 5,000/day per IP. Full reference: /api/.

2. Use our Custom GPT in ChatGPT — zero setup

We published Coin Flip — Verified Fair on the ChatGPT GPT Store. Click the link, then just chat: “Flip a coin to decide between pizza and burger.” No setup, no schema, no install — ChatGPT calls our API for you and cites the verify URL. Works on any paid ChatGPT plan (Go, Plus, Pro, Business, Enterprise). Sign-in is required for the GPT’s Action to actually run.

3. Use the MCP server with Claude Desktop, Claude Code & Gemini CLI

We published an official Model Context Protocol server: flip-a-coin-mcp on npm. One command in Claude Code or a small JSON block in Claude Desktop and Claude can flip coins natively. The same package also works with Gemini CLI — Google’s terminal AI tool that speaks MCP (consumer Gemini chat and Gems don’t support third-party MCP yet, but the CLI does). Three tools: flip_coin, flip_coin_many (1–100,000), and verify_flip. Setup details for all three on /ai-integration/.

4. Every API flip gets a verifiable URL

Every call — whether from the GPT, the MCP server, or a direct HTTP request — receives a 16-character flip ID and a citable verify_url that anyone can visit for 30 days. The verify page shows the coin, the count, the timestamp, and the full sequence (up to 10,000 tokens inline for multi-flip runs).

Live sample — a fresh 100-flip Yes/No run we just made for this post: https://flip-a-coin.com/flip/4a004d5a6d0849c3

Documentation

• flip-a-coin.com/ai-integration/ — how to use the GPT, MCP, and copy-paste prompts in any AI assistant.
• flip-a-coin.com/api/ — full developer reference, parameter table, OpenAPI 3.1 schema, and code examples.

You can now embed the coin flip on your own site — no JavaScript, no accounts. Just paste a single <iframe> tag into any blog post, lesson page, or article.

The new Embed the Coin Flip Widget generator lets you:

• Pick from our widget catalog — United States coins (Penny through Presidential Dollar and the 50 State Quarters), Flip a Coin.com’s own Decision Making Coins (Heads/Tails, Yes/No, Go/Stay, and others), and selected cryptocurrencies (Bitcoin, Cardano).
• Customize the Heads and Tails labels (e.g., “Pizza” / “Burger”).
• Match your site with auto/light/dark theme, palette or custom #hex background, and adjustable text size.
• Set the iframe width and height to fit your layout.

Every flip is cryptographically fair (crypto.getRandomValues()) and counts separately on our Statistics page. No tracking cookies are set inside the iframe. Works on all modern browsers, including mobile.

Try it now: head over to flip-a-coin.com/widget/, configure your widget, copy the code, and paste it anywhere.

• Four new articles
  • How to Flip a Coin: A Step-by-Step Guide — the conventional thumb-flick technique broken into eight numbered steps, plus the two standard catch methods (sandwich and backhand). Honest about the “heavier side” myth and which catch the NFL actually uses.
  • Why the Martingale Strategy Isn’t a Guaranteed Win: A Math Lesson in Ruin — the famous “double after every loss” system, the geometric-sum math that makes it look airtight, and the three hidden assumptions (infinite bankroll, no table limit, fair coin) that make it fail in practice. Featuring Doob’s Optional Stopping Theorem.
  • Why First Kickers Tend to Win Soccer Penalty Shootouts — Apesteguia & Palacios-Huerta’s headline 60/40 first-kicker advantage, the UEFA/FA ABBA-order trial, IFAB’s 2018 decision to end the experiment, and what the more recent Pipke 2025 replication has to say.
  • Is This Coin Loaded? A Hypothesis Test Walkthrough — 17 heads out of 20 flips. Is the coin loaded? The full binomial-test walkthrough, two-tailed p-value, and what a 5% vs 1% significance level actually means in practice.

• Two new articles
  • Coin Flip Statistics Simulator — A Hands-On Tool for the Probability Classroom — four interactive simulators (Law of Large Numbers, Random Walk, Bell Curve, Streaks) that run live in the browser using crypto.getRandomValues. A hands-on teaching companion to the math.
  • Shogi’s Coin Toss: How Furigoma Decides Who Moves First — the 5-pawn ritual that has settled who plays first in Japanese chess for nearly four centuries, with the 1,541-toss JSA fairness dataset and the Edo-period origin story.
• Statistics page upgraded — Statistics now includes a live Z-test and chi-squared fairness check on the site’s cumulative flips, plus in-browser Law-of-Large-Numbers and Random Walk simulations that refresh every visit.

• Dayflow added — a new default background that matches your current time of day. Each visit picks one of five themes based on your local clock, no setup required.
• Time-of-day themes
  • Morning (5:00–10:30) — Fresh Light, calm cream and cool blue tones to start the day
  • Afternoon (10:30–17:00) — Calm Daylight, soft pastel blue and peach for a settled mood
  • Evening (17:00–20:00) — Golden Hour, warm sunset copper and magenta for an emotional shift
  • Night (20:00–0:30) — Neon Chill, deep violet with neon cyan and magenta accents
  • Midnight (0:30–5:00) — Midnight Aurora, quiet navy with shimmering green and purple aurora
• Pick your own theme anytime — open Select Background to lock in any single Dayflow theme, or keep Dayflow active so it picks the right one for you on each visit.

• Dark Mode added — the entire site now supports a dark theme. Toggle between System, Light, and Dark with the Dark Mode button in the footer.
• Remembers your choice — your preference is saved locally and applied instantly on every visit.
• System mode follows your OS — System is the default; the theme automatically matches your OS appearance and updates live when you change it.

• New background: Midnight Aurora — a calm, CSS-rendered animated background with subtle drifting aurora lights. Now available in the Select Background modal (and set as the new default).
• Rotating question text on the homepage — the homepage now shows a curated stream of real-life decision prompts (over 200 questions, including time-of-day specific ones like Monday-morning or Friday-night picks). Just tap the coin while a question is showing and the flip becomes the answer to that exact question.
• Edit the question — make it your own — tap the question text to type your own. You can also edit the Heads / Tails labels to whatever the two options are (e.g. Pizza / Sushi, Go / Stay). The flip then decides between your two choices, not a generic Heads or Tails.
• Question text on Decision Making coins too — coin pages like Yes or No, Coffee or Tea, and Start or Stop now show the question above the coin in the same style, so every Decision Making coin reads as a clear yes/no prompt.
• Custom labels that stick — set your own front and back labels on a Decision Making coin (up to 30 characters, with emoji ✨) and they persist across reloads so you can keep using the same custom flip.
• Share the exact flip — every result now has a Share button that copies a URL carrying your question, both labels, and which side landed (?q=&f=&b=&r=). The person you share with opens the page and sees the same question and the same result you got — perfect for settling decisions over chat.

• Choose any flip count from 1 to 100,000 — the new “Specify flips” input lets you type any number and jump straight to that page. Available inside the “Select Number of Flips” modal and in the “Want to flip more?” section on every flip page.
• Three new preset counts: 50, 500, and 100,000 — the preset list now offers 12 counts (1, 2, 3, 4, 5, 10, 50, 100, 500, 1,000, 10,000, 100,000) for quicker access to common scenarios.
• Smart pre-fill — when you visit a specific flip-count page (e.g. /flip-a-coin-66666-times/), the Specify flips input is pre-filled with that number so you can easily tweak it.
• Updated Statistics page — added a “Top 10 Flip Counts” chart showing the most popular flip counts chosen by users.

• Copy result to clipboard — a new “Copy result” button has been added next to the “Details of the result” modal text. Tap it to copy the full H / T sequence in one tap.
• Faster page loads — coin and background images now use WebP, heavy modal contents are loaded on demand, and analytics scripts are deferred until after first interaction. Mobile Lighthouse score improved by about 45 percent.
• Cookie-free site preferences — your settings (selected coin, background, BGM track, audio on/off, history, custom labels and images) are now kept entirely in your browser via local storage. No preference data is sent to our server.

• What’s New section launched — site updates are now logged here. Full history: /whats-new/
• Statistics page — see /statistics/ for live aggregate data and Heads/Tails fairness charts.
• Customize coin images — upload your own front / back images on any flip page (PNG, JPG, WebP, animated GIF). Stored on your device only.
• Customize Heads / Tails labels — rename the coin sides to anything (e.g. “Pizza” vs “Burger”). Click the pencil icon next to the coin name.
• Keyboard shortcuts — press SPACE to flip (works during the result panel too), ESC to dismiss the result.
• Smoother single-flip animation — front and back faces now alternate visibly during the toss, matching multi-flip behavior.
• Result panel auto-closes back to menu — the coin name and edit button are restored automatically when the result is dismissed.
• Bet game button renamed to “Game” — the header button label is clearer.