• Remove Qtum references in translate file

Htmlcoin 2.5.1 Changelog

  • Add height as argument for getsubsidy

  • Fix coinbase generation for getwork

  • Add getcontractcode method to get code from contract

  • Checkpoint sync switch to checkpointed chain

  • Correction of SegWit activation height on testnet

  • Checkpoint sync use block index when checking headers

  • Add missing hyphen to hidden arg checkpointdepth

  • estimatesmartfee to return min value if not enough data

  • Update AssumeValid, ChainWork and ChainTxData

Htmlcoin 2.5.0 Changelog

Htmlcoincore 0.19 Overview

Mandatory upgrade due to hard fork on block 1,284,400. This is to implement several new features listed below.

  • QIP-5: Signature proofs within vout scripts for contract transactions

  • QIP-6: Add btc_ecrecover precompiled contract to HTML EVM

  • QIP-7: Upgrade to the Ethereum Constantinople version of EVM

  • QIP-9: Change PoS difficulty adjustment algorithm to cause less swings in PoS block time

Also included in this release:

  • Staker optimizations: better performance for big wallets and improved UTXO aggregation

  • New GUI, New features, Security improvements and Bug fixes

  • Upgrade to bitcoin core 0.19

2 More “Block Relay Only” Peers

Htmlcoin Core (and Bitcoin core 0.19) made “outgoing” connections to 8 peers for previous versions. This is the count of nodes you would see with the node operating on a home network where port 3888 was not open for “incoming” connections. With version 0.19 this count of peer connections is increased by 2 to give a total of 10. The last two peers added (at initial startup) will be “block relay only” peers: they will verify and relay blocks only, not all the transactions.

You can identify the “block relay only” peers using the getpeerinfo command and look for “relaytxes”: false. These extra “block relay only” peers are a network security improvement.

More Korean and Chinese Translations

Additional pages in the wallet received translations for Hangul and Mandarin. To change the language for the wallet, go to Settings — Options — Display — User interface language to select (한국어 ko, 简体中文-中国 zh_CN), then restart the wallet to display the new language.

New Korean and Chinese translations

Say Goodbye to Windows 32-Bit Version

With this version of Htmlcoin Core (and Bitcoin Core) support for Windows 32-bit versions has ended, with the motivation being fewer versions to test (only one version per platform now). Microsoft recently ended support for Windows 7 updates (security patches) as well. If your Windows computer is using 32-bits or Windows 7 it is time to think about a new computer.

New and Revised Commands

There are several new commands and many commands have new or changed parameters. Keep in mind that you can get the details about any command using “help command_name”.

The new commands are:

getbalances gives wallet balances for trusted, untrusted_pending and immature balances.

setwalletflag gives control of specific functions such as avoid_reuse.

getblockfilter retrieves the BIP 157 content from a specific block. BIP 157 is a new light client protocol, see Reference B for more details.

UTXOHash Added

“UTXOHash” was added to the results of the callcontract command. This provides a hash from the EVM UTXO state, to make it easier to manage UTXOs through the Account Abstraction Layer (which interfaces the core blockchain UTXO model and EVM account model).

Htmlcoincore 0.18.2 Overview

Every Htmlcoin update brings new features and bug fixes, however, the 0.18.2 release stands out as one of the most interesting and exciting Htmlcoin releases in the past two years.

Here's some highlights of this new release:

  • New UI, with different themes to choose from (Light, Dark Blue and Dark)

  • New RPC calls added: signrawsendertransactionwithwallet and signrawsendertransactionwithkey

  • Build fixes on some platforms

  • Bug fixes

Let's review the UI which changes the user experience completely:

Switching Themes

Changing themes is a breeze, all we need to do is go to Preferences -> Display and choose the user interface style, once you choose the new style, click on "ok" and your wallet will restart with the new theme.

Wallet Backup Reminder

Htmlcoin 0.18.2 has a very useful wallet backup reminder, here's a couple of screenshots showing how it looks and works:

We get this reminder on when the wallet launches for the first time, we can decide to backup later or backup now (recommended).

You'll be asked where to save the wallet backup here

Staking Button

Another new, cool feature about the 0.18.2 Htmlcoin release is the Staking Button, it enables staking on your Htmlcoin wallet by simply pressing the above button, if the wallet is encrypted, you'll be asked to unlock the wallet.

Here we unlock the wallet and decide if we want to fully unlock or unlock for staking only.

Htmlcoin 2.4.2 Changelog

  • Update checkpoint sync key.

Htmlcoin 2.4.1 Changelog

  • Remove unused mining key and fix getwork crash when submitting block.

Htmlcoin 2.4.0 Changelog

  • Add header signature verification (soft fork at block 997,655).

  • Upgrade to Bitcoin core 0.18.0

  • Add support for bitcore RPC calls, configure with ./configure --enable-bitcore-rpc to enable.

  • Update nMinimumChainWork, ChainTxData and defaultAssumeValid using recent chain data.

Thanks to Qtum for their continued hard work developing their project which is upstream of HTMLCOIN. For more information about changes in this new HTMLCOIN version look at the Qtum release page linked below, applicable versions 0.17.0 to 0.18.0.


Htmlcoin 2.3.1 Changelog

  • Set minimum accepted P2P connection to 70007 (2.3.0)

  • Enable new version notification pop up when starting Qt client

  • Request PoW blocks from getblocktemplate and not PoS

Htmlcoin 2.3.0 Changelog


  • On block 626,000 the difficulty algorithm will change for both PoW and PoS. PoS will use Qtum's difficulty adjust. PoW will use the same solution used by Dash. The current difficulty algorithm tends to oscillate either too high or too low. Having the difficulty adjusted separately for each type of block generally allows one type to cover for the other when the difficulty is left too high, but a more accurate difficulty solution is required hence the hard fork.

  • No longer provide contract transactions to getblocktemplate. This is typically used by pools or mining software that construct the entire block external to HTMLCOIN. As no external mining software that creates blocks has yet added support for contract refund transactions in the coinbase, then providing contract transactions can prove problematic, as refund transactions not being present will cause those blocks to be rejected by the network. This combined with the oscillating difficulty adjust could leave HTMLCOIN with long periods of no blocks, this has been temporarily remedied by contacting the major mining pools and asking them to disable contract staking. This change is not part of the consensus rules so external mining software can enable contract transactions in getblocktemplate, if they succeed in supporting contract refund transactions.

  • Combine loops in the soon to be legacy difficulty adjust algorithm to prevent looping over the same set of blocks twice.

Htmlcoin 2.2.0 Changelog

  • Upgrade to Bitcoin core 0.16

  • Only request blocks from peers when their chainwork is strictly greater than the current tip

  • Add extra header checks for PoS timestamp, block indexes, signature type (LowS), synchronized and rolling checkpoints.

  • Update nMinimumChainWork, defaultAssumeValid and chainTxData

  • Implement network spam protection

  • BIP173 (Bech32) Address support (“hc…” addresses)

  • HD-wallets by default

Htmlcoin 2.1.2 Changelog

Denial-of-Service vulnerability

A denial-of-service vulnerability (CVE-2018-17144) exploitable by miners has been discovered in HTMLCOIN Core versions 2.0 and 2.1. It is recommended to upgrade any of the vulnerable versions to 0.16.3 as soon as possible.

Htmlcoin Changelog

Update Solidity and Token template links.

Htmlcoin Changelog

Fix for rare case where checkpoint is not initialised.

Htmlcoin Changelog


Updated release of HTMLCOIN 2.0 to include a correction of the eHRC difficulty adjust, PoS and PoW are calculated separately, when calculating one blocks from the other are skipped, the iterator that counts the number of blocks sampled was incremented even when blocks of the wrong type were skipped causing unexpected problems in the wild. This release fixes this issue at block height 7,700, make sure you have upgraded before then.

If you used the Windows installer for HTMLCOIN please uninstall it first as the installation folder has changed to avoid a conflict with HTMLCOIN 1.x, the new version of the client will install to Program Files in a folder called HTMLCOIN2.

Please do not make any changes to the data directory that contains your wallet.dat, it will remain unchanged by the uninstaller, installer or new client. It is always wise to back up your wallet.dat and can be done so from the File menu in either or