The Polygon mempool — more precisely each node's txpool — is where transactions wait between the moment you sign them and the moment a block includes them. The live panel above reads a public Polygon RPC node every 6 seconds: how many transactions are pending, how many are queued behind nonce gaps, the current base fee, and a preview of the next block sorted by tip.
On a network with two-second blocks, "pending" should last about as long as it takes to blink. When a Polygon transaction stays pending for minutes, something specific is wrong, and it's almost always fixable. This page explains how to read the mempool, why transactions get stuck, and how to speed up, cancel or replace one.
Quick answer
A stuck Polygon transaction usually has a tip below the network minimum or is blocked by an earlier transaction with a lower nonce. Fix it by sending a replacement with the same nonce and at least ~10% higher fees — MetaMask's Speed up and Cancel buttons do this for you.
What the Polygon mempool is (and why there isn't just one)
People talk about "the mempool" as if it were one big public waiting room. It isn't. Every Polygon node keeps its own txpool — its own list of transactions it has heard about but hasn't seen included in a block. Transactions spread from node to node over the peer-to-peer network, so pools look similar but never identical.
That has two practical consequences. First, the numbers in our widget come from one public node (the same RPC our live explorer uses) and will differ slightly from what another node reports. Second, a transaction can be "pending" on the node your wallet talks to and completely unknown elsewhere. When an explorer can't find your fresh hash at all, that's usually why.
When we queried the node on the morning of 25 September 2026, txpool_status reported about 32,500 pending and 17 queued transactions. That sounds like a lot until you remember a Polygon block can hold 160 million gas; most of that pool is low-priority, bot-driven or replaced traffic, not a traffic jam blocking your payment.
Reading the live mempool widget
The widget shows four things. Here's how to interpret each.
| Field | Meaning |
|---|---|
| Pending in txpool | Executable txs waiting for a block |
| Queued | Txs blocked by a missing earlier nonce |
| Base fee | Protocol fee per gas, burned (gwei) |
| Next block preview | Top 8 txs by tip, from the pending block |
Pending transactions are ready: their nonce is next in line for their sender and the fee is acceptable. Queued transactions are parked because the sender has a gap — say nonce 41 is missing, so 42, 43 and 44 wait. A high queued count on your own address is the clearest possible sign of a nonce problem.
The next block preview comes from asking the node for its pending block — its best guess at what the next block will contain. We sort it by priority fee, so you see who is paying the most to get in. Click any hash to open it in our transaction lookup. In our check, the lowest tip in that preview was exactly 25 gwei and the median around 75 gwei, while some bots paid 450 gwei. If your transaction's tip sits well below the bottom of that list, it won't be picked soon.
For the full picture of current fees — slow, standard and fast prices in gwei, and what a transfer costs in POL and USD — use our Polygon gas tracker. The mempool widget answers "what's waiting"; the gas tracker answers "what should I pay".
Why Polygon transactions get stuck
In our experience helping readers, stuck Polygon transactions come down to four causes.
1. The tip is too low
Since EIP-1559-style fees arrived, a Polygon transaction pays a base fee (burned) plus a priority fee or tip (to the block producer). Polygon nodes enforce a minimum tip. If you or a dApp set a custom gas value below it — or a wallet used a stale estimate during a spike — the transaction may sit indefinitely or be rejected outright. Base fee also rises when blocks are busy, so a max fee that was fine a minute ago can fall below the new base fee.
2. A nonce gap
Every transaction from an address carries a nonce: 0, 1, 2 and so on. Nodes process them strictly in order. If nonce 57 is stuck with a low fee, nonces 58, 59 and 60 wait behind it, no matter how generous their fees. This is the classic "I sent five transactions and none go through" situation. The fix is always to deal with the lowest pending nonce first.
3. The transaction never propagated
Sometimes the RPC your wallet uses accepts a transaction and never forwards it. No explorer ever sees it. The wallet shows "pending" forever. Switching to a different RPC and rebroadcasting or replacing it usually solves this — our network settings page lists working public endpoints.
4. The wallet is out of sync
Less common, but real: the transaction actually confirmed or was dropped, and your wallet's display didn't update. Always check the hash on an explorer before doing anything drastic.
How to speed up or cancel a transaction in MetaMask
MetaMask and most major wallets build nonce replacement into two buttons. Open the pending transaction in your wallet's Activity tab.
- Check the hash first. Paste it into our Polygon transaction explorer or PolygonScan. If it already shows Success or Fail, there's nothing to fix — refresh the wallet.
- Choose Speed up to keep the same transaction but pay more. MetaMask resubmits it with the same nonce and higher max fee and tip. Use this when you still want the payment to go through.
- Choose Cancel to abandon it. MetaMask sends a zero-value transaction to your own address with the same nonce and a higher fee. Whichever lands first wins; the other is discarded.
- Confirm and watch. On Polygon the replacement usually confirms within a few seconds. The original hash will then show as replaced or dropped, and a new hash takes its place.
Wallet interfaces change often, and some wallets hide these buttons for certain transaction types. If yours doesn't offer them, the manual method below always works.
Replacing a transaction by nonce (the manual way)
This is what Speed up and Cancel do under the hood, and you can do it yourself in any wallet that lets you set a custom nonce. In MetaMask, turn on "Customize transaction nonce" in the advanced settings first.
- Find the stuck nonce. Open the transaction on an explorer; the Nonce field is listed with the other details. Or use the lowest nonce your wallet shows as pending.
- Build the replacement. Same "from" address, same nonce. For a cancel: send 0 POL to yourself. For a speed-up: repeat the original transaction.
- Raise the fees enough. Nodes only accept a replacement if both the max fee and the priority fee are higher than the original by a margin — about 10% on standard Geth-based nodes, which is what Polygon's Bor client is built on. We usually go 20–30% higher to be safe, then check that the tip is comfortably above the lowest tips in the next-block preview.
- Submit and verify. Look up the new hash. Once it confirms, the nonce is used and the original can never execute.
| Action | Same nonce | Value / recipient | Result |
|---|---|---|---|
| Speed up | Yes | Unchanged | Original intent, higher fee |
| Cancel | Yes | 0 POL to yourself | Original voided |
| New send | No | Anything | Original still pending |
If several transactions are stuck behind a gap, replace the lowest nonce first. The rest will usually flow through on their own within a couple of blocks.
Replacing needs a little POL for the higher fee. If your wallet is empty, buy POL on a regulated exchange that holds licences in several jurisdictions and lets you withdraw directly to the Polygon network — make sure the withdrawal network is Polygon PoS before you confirm.
Reading pending status on Polygon explorers
Explorers handle unconfirmed transactions differently, and it's worth knowing their quirks.
- PolygonScan shows a status of Pending for transactions its nodes have seen, along with a pending transactions list. Replaced transactions are eventually marked as dropped or replaced.
- Blockscout focuses on confirmed data. In our test its pending-transaction filter for Polygon returned an empty list, so don't rely on it for mempool visibility.
- Our live explorer looks up confirmed transactions via Blockscout and falls back to direct RPC calls, so it can often find a very recent hash. If it says the transaction wasn't found, wait a few seconds and try again, then check PolygonScan.
A transaction that no explorer can find after a minute or two most likely never left your wallet's RPC. Replace it through a different endpoint. Our step-by-step guide to checking a Polygon transaction explains what each status means once it does confirm, including why a confirmed transaction can still show Fail.
For developers: querying the txpool yourself
If you're building a tool, the widget's data comes from two JSON-RPC calls you can make yourself against a public endpoint:
curl -s https://polygon-bor-rpc.publicnode.com \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"txpool_status","params":[]}'
# {"jsonrpc":"2.0","id":1,"result":{"pending":"0x7ee5","queued":"0x11"}}The values are hex: 0x7ee5 is 32,485 pending, 0x11 is 17 queued. The second call is eth_getBlockByNumber with ["pending", true], which returns the node's candidate next block with full transaction objects. Not every provider exposes txpool_* methods — dRPC's public endpoint rejected txpool_status as unavailable when we tested. Our Polygon explorer API guide lists which endpoints support what, and ethereum.org's gas documentation explains the base fee and tip model Polygon inherits.
When you're choosing an explorer for day-to-day checks, our ranking of the best Polygon explorers compares how each handles pending and failed transactions — PolygonScan remains the strongest for mempool visibility.