Check the address before you send.
One wrong character, one wrong network — or one wrong token — and the funds are gone. SendCheck runs a pre-flight on any EVM address: checksum, activity on the exact chain you're sending on, wallet or contract, native + USDC + USDT balances — including the classic "this address holds USDT, not USDC" trap. Free. No account. Runs in your browser.
Free: 3 checks per day per browser. Your address only leaves your browser to go to public chain nodes — we store nothing.
No wallet handy? Jump to the tip jar below and send any amount — USDC on Base.
What SendCheck catches
❌ Typos & tampering
Full EIP-55 checksum verification in your browser. A mixed-case address whose casing doesn't match its own Keccak-256 hash is a typo, a dropped character, or clipboard malware — and we show you the correct form.
🔶 Wrong network
The classic loss: a perfectly valid address — but one that has never been used on the chain you're sending on, while it's clearly active elsewhere. The deep scan checks all five supported networks and flags the mismatch in plain language.
🏦 Contracts & cold addresses
Smart-contract destinations, brand-new zero-activity addresses, and burn addresses get their own warnings, plus native, USDC and USDT balances so you can sanity-check what you're about to do.
💱 Wrong token (USDT ≠ USDC)
Dollar-pegged does not mean interchangeable. If the address clearly lives in the USDT world (holds USDT, almost no USDC), SendCheck says so before you hand over the wrong stablecoin — exchanges don't auto-swap tokens.
New from the forge: USDC Variant Resolver — two tokens can both be called USDC (Circle-native vs bridged USDC.e / USDbC). Paste the token address you were given and see exactly what it is on each chain, free.
SendCheck Pro — 0.50 USDC, once
No daily cap. No account. No subscription. A one-time payment straight on Base that the page verifies itself — your unlock is a transaction hash, re-checkable by anyone on the explorer. The free tier (3 checks a day) stays free forever.
- ✓ Unlimited address checks on all five chains
- ✓ Everything the free tier does: checksum, wrong-network, wrong-token, contract & balance data
- ✓ Verified on-chain in your browser — no email, no login, no third party in between
- ✓ Pay in one click from any browser wallet (MetaMask, Brave, Coinbase Wallet) — or copy the address
Buying from a link? The full buy page with the payment steps and FAQ: sendcheck.surge.sh/pro.html — it also carries a hosted checkout (NOWPayments) if you'd rather not copy an address: USDC from any wallet, no account or email.
FAQ
Does a passing checksum mean it's my counterparty's address?
No. The checksum proves the string wasn't garbled in transit — it's a spell-check, not a payee verification. Always confirm an address with the other party through a second channel (voice, in person, their verified channel).
Why does the same address work on many chains?
Ethereum, Base, Arbitrum, Optimism and Polygon are all EVM networks sharing one address system — the same private key maps to the same address on every one of them. Balances, however, are separate per chain. That's exactly why the wrong-network check exists.
What happens to my address? Do you store it?
Nothing is stored, logged or sold. The page queries public chain nodes (one JSON-RPC per check) and computes the rest locally. No cookies, no accounts, no analytics.
How does the share link work? Does it store anything?
The link only carries the address and chain in the URL. When someone opens it, their browser runs the same live check again from scratch — it's a pointer to a fresh verification, not a saved result. We never see who shared what. Opening a shared link costs the viewer nothing: it doesn't touch their 3 free daily checks.
Which chains are supported?
Base, Ethereum, Arbitrum One, Optimism and Polygon — the five networks that share the most USDC volume. The tool works with any EVM address format.
Are USDC and USDT the same thing?
No. Both are dollar-pegged stablecoins, but they are issued by different companies (Circle vs Tether) and are separate tokens on every chain — an address can hold USDT and zero USDC. SendCheck shows both balances and warns when an address looks like a USDT wallet while you're about to send USDC.
What happens to my tip?
It goes straight on-chain — a USDC transfer on Base to the public address on this page. No payment processor, no middleman: you (and anyone else) can verify it on the Base explorer. Tips keep the public RPCs warm and fund the next tool in the forge. They're separate from Pro — though because the tip jar and the Pro payment share the same on-chain address, a tip of 0.50 or more can double as a valid Pro proof if you paste its hash into the Pro box. Same receipt, either way.
Is SendCheck affiliated with any wallet or exchange?
No. It's an independent tool by Pennyforge, a small one-person studio. Data comes from public RPC endpoints, not from any exchange.
Can I use it offline?
The checksum part, yes. The on-chain part needs one public node per chain — no API key required.