🔔 Crypto Live Alert Board

Live Binance prices, 24h change and RSI(14) for up to 20 coins, with price, fast-move and RSI alerts. Browser-only, nothing sent to a server. Not advice.

Loading Data: Binance public API and WebSocket (spot USDT); KRW conversion at Bithumb's USDT/KRW

Bar

Add an alert rule

Alert log

Export / import settings

Prices are Binance spot USDT; KRW is a reference conversion at Bithumb's USDT/KRW. RSI(14) rules and price rules on the "bar close" basis use closed bars only; "live touch" and fast-move rules use the WebSocket price (about once a second). A rule that has fired stays quiet until price moves 0.1% back past the alert price, RSI returns below 68 (above 32 for the 30 rule), or the move falls under half the threshold.

Rules keep being checked from WebSocket prices while the tab is hidden. On phones or in power-saving mode the browser may freeze the tab or drop the connection, and no alerts arrive during that time. Closing this page stops the alerts. Settings and the log stay in this browser only and are never sent to a server.

For information only, not investment advice. Data comes from exchanges' public APIs and may be delayed or interrupted. Charts: TradingView Lightweight Charts™

What this tool does

A board that keeps live prices for up to 20 coins on cards and alerts you when conditions you set are met. Each card shows the price in USDT with a KRW conversion, 24h change, the change of the forming bar on the chosen timeframe (5m, 15m or 1h), and RSI(14) of the last closed bar. There are three rule types: price at or above / at or below an alert price (bar close or live touch), a fast move within N minutes, and RSI entering 70+ or 30−. Prices come straight from Binance's public spot USDT API and WebSocket to your browser, and rules and the log are stored only in this browser. It opens with BTC, ETH, SOL, XRP, BNB and DOGE and no rules.

How it is calculated

For each coin the last 200 bars of the chosen timeframe are fetched once from the public API; after that, one combined WebSocket stream delivers the forming bar (kline) and 24h ticker (miniTicker, about once a second) for every coin. A 'live touch' price rule fires the moment an incoming price reaches the alert price; a 'bar close' rule checks the close when the bar closes. A fast-move rule compares the current price with the lowest price of the last N minutes (1, 5, 15, 30 or 60) for a rise of +Y% or more, and with the highest price for a drop of −Y% or more. The price history is seeded with 1-minute closes and then built from live prices at 1-second spacing. RSI uses 14-bar Wilder smoothing, computed in the browser on closed bars only. A rule that has fired rests until it moves back: price rules re-arm 0.1% back past the alert price, the RSI 70 rule below 68 (the 30 rule above 32), and fast-move rules when the move shrinks under half the threshold. If a rule is already inside its condition when added, it does not fire immediately and starts watching after the condition is left once.

Type a symbol (e.g. ADA) in the top box and press Add. Up to 20 coins; remove one with the × on its card (its rules go with it)

Pick 5m, 15m or 1h under Bar. Forming change, RSI, bar-close price rules and RSI rules use this timeframe

In 'Add an alert rule', choose the coin and type and enter values. The '+ Alert rule' button on a card preselects that coin. Up to 10 rules per coin

Press the sound button to hear alerts and 'Enable browser alerts' for notifications (the permission prompt appears only when you press it). 'Test alert' lets you check them first

Fired alerts are listed in the alert log with time, coin, rule and value (latest 200). Use 'Export / import settings' to move your setup to another device

Reading each section

Top bar: timeframe, adding coins, connection

Bar applies 5m, 15m or 1h to every coin. Changing it refetches bars and restarts bar-close price rules and RSI rules on the new timeframe (live-touch and fast-move rules do not depend on it). The input accepts a bare symbol like BTC and suggests the top 100 coins by volume. On the right are the connection mode (Binance WebSocket, backup WebSocket or polling every 15 s) and the last receive time. The address bar keeps the coin list and timeframe as ?c=BTC,ETH&tf=15m (rules are not put in the address).

Alert buttons

With sound on, each alert plays two short tones (at most once every 1.5 s even if several rules fire together). 'Enable browser alerts' asks the browser for permission; once allowed, alerts appear as system notifications even when the tab is hidden. If you blocked them, change it in the browser's site settings. When an alert fires, the tab title blinks as '(count) 🔔 coin alert' — 10 times while you are looking, or until you return if the tab is hidden. 'Test alert' tries all three once, regardless of rules.

Rule form

A price rule takes at or above / at or below, an alert price in USDT and a basis (bar close or live touch). A fast-move rule takes a window (1, 5, 15, 30 or 60 minutes), a threshold (0.05–50%) and a direction (either way, up or down). An RSI rule is either entering 70 or above or entering 30 or below. Duplicate rules are not allowed and each coin holds up to 10. Below the form you see the coin's current price and how the rule is judged.

Coin cards

The large number is the price in USDT, with a KRW reference converted at Bithumb's USDT/KRW below it (it can differ from Korean exchanges' KRW prices). 24h is current price ÷ price 24 hours ago − 1, 'forming' is the change of the bar not yet closed from its open, and RSI is RSI(14) of the last closed bar, coloured at 70+ or 30−. The dot on each rule line shows its state: green 'Armed' (fires when met), amber 'Fired · re-arms after moving back' or 'Already inside', grey 'Checking' (no price yet). A card's border lights up briefly when one of its rules fires.

Leaving it open

Incoming WebSocket prices are used for rule checks right away even while the tab is hidden; only drawing is batched to the browser's repaint and paused while hidden. After more than a minute away, bars are refetched for every coin on return. If the connection drops it reconnects after 1, 2, 4… seconds (up to 30), moves to a backup address after three failures in a row, and falls back to polling every 15 seconds if that fails too. Polling is set to continue while the tab is hidden, but it slows down as much as the browser throttles hidden-tab timers. Bars that closed while disconnected are fetched and checked, but bars that closed more than 2 minutes ago only update rule state without firing. Phones often freeze pages when the screen turns off or you switch apps, so a desktop browser is better for long sessions.

Things to know

On short bars a 'live touch' rule can fire often near the line. Use the 'bar close' basis or a longer timeframe to reduce noise

Short windows with small thresholds fire often. 15 minutes and 2% fires less than 1 minute and 0.5%

RSI 70 and 30 are conventional lines. In strong trends RSI can stay in the zone for a long time, and the rule will not fire again meanwhile

Browsers only allow sound after you click or press a key on the page. After a reload, click the page once

'Add example rules' adds ±2% alert prices, a 15-minute ±2% move and RSI 70/30 rules to BTC (or the first coin). They are samples to edit

Frequently asked questions

Do alerts still arrive if I switch tabs or minimise the window?

While this page is open, rules keep being checked from WebSocket prices even when the tab is hidden; only drawing pauses. On phones or in power-saving mode the browser may freeze the tab or drop the connection, and no alerts arrive during that time. Closing the page stops alerts. There is no server watching on your behalf.

What is the difference between 'bar close' and 'live touch'?

Live touch fires the moment price reaches the alert price. Bar close fires only if the close of the chosen bar (5m, 15m or 1h) is past the alert price when the bar closes, so a brief touch that reverses inside the bar does not fire. The trade-off is waiting for the bar to close.

Will the same alert keep ringing?

No. A rule that has fired stays quiet until it moves back: 0.1% back past the alert price for price rules, below 68 (above 32 for the 30 rule) for RSI rules, and under half the threshold for fast-move rules. Each rule line on the card shows 'Armed' or 'Fired · re-arms after moving back'.

Where are rules and the log stored? Are alerts buy or sell signals?

The coin list, rules, sound setting and alert log stay in this browser's storage (localStorage) and are never sent to a server. An alert only means a condition you chose was met; this tool does not recommend any trade.

For information only, not investment advice. Data comes from exchanges' public APIs and may be delayed or interrupted.