Bitcoin Core 30.0’s release on October 10 was accompanied by a lot of concern about the increased OP_RETURN relay defaults (namely, allowing multiple OP_RETURN outputs per transaction, and allowing up to 100kB of data in OP_RETURN outputs). It’s now been a few months since then, so we can examine confirmed transactions to how much impact those changes have had. I did this previously and reported some results on 27 Sep 2025.
Looking at blocks 915800 (22 Sep 2025) to 936000 (11 Feb 2026), I get the following results:
- 24,362,310 txs with OP_RETURN outputs, and 24,363,011 individual OP_RETURN outputs
- 61 txs with multiple OP_RETURN outputs (eg 927203:312 with 91 OP_RETURN outputs)
- 396 txs with total OP_RETURN scriptPubKey sizes greater than 83 bytes (42 of these had multiple outputs, eg 925209:39 which had 1393 bytes total but only 66 bytes in its largest output), collectively 2,093,184 bytes of scriptPubKey data. Here’s the distribution of sizes – you can see 50% of txs have less than 210 bytes of OP_RETURN data, but equally 50% have more than that; 10% have more than 10kB of OP_RETURN data.
data:
- x: [84,84,84,84,84,84,85,85,85,86,86,86,86,86,86,86,86,86,86,86,86,86,86,86,87,87,87,87,87,87,87,87,87,88,88,88,88,88,88,88,88,89,89,89,90,90,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,91,93,94,94,94,94,95,95,95,96,97,97,99,99,99,100,100,100,101,102,102,102,102,102,102,103,104,108,110,111,111,111,113,113,113,115,116,117,117,117,117,118,118,118,118,118,118,118,118,118,118,118,118,118,118,118,118,118,119,119,119,119,120,121,122,122,123,125,126,127,127,127,127,128,128,128,130,131,134,134,135,135,135,136,136,136,137,137,137,138,139,139,140,141,144,145,147,149,149,149,150,155,156,156,157,158,167,168,169,171,171,171,177,177,180,180,180,180,185,189,195,199,199,199,203,204,209,210,211,213,214,219,225,225,226,229,236,239,244,246,246,248,250,254,254,255,255,256,261,262,264,266,268,268,268,271,271,272,275,276,279,280,289,291,293,293,293,296,297,297,298,298,301,302,305,307,310,317,318,322,323,327,339,341,343,344,349,355,359,360,367,374,375,380,385,400,407,409,418,469,471,484,494,500,503,534,535,550,558,650,710,716,726,744,757,769,775,788,879,901,911,915,915,915,970,990,1003,1008,1016,1016,1016,1016,1030,1030,1030,1063,1109,1145,1165,1188,1201,1274,1277,1343,1365,1365,1365,1365,1365,1365,1365,1368,1393,1502,1503,1555,1555,1583,1675,1721,1762,2019,2124,2200,2350,2663,2683,2817,2954,3633,3685,3699,4090,4567,4727,5558,5560,6198,6955,7987,9075,9193,9284,9676,9676,9808,10513,10636,11383,12448,13438,14153,14624,15410,15551,21635,23845,24460,24673,25911,28620,29119,29775,30195,33174,34146,40460,42685,67974,70884,82614,82615,82617,82626,82626,82627,82628,82628,82634,82641,86826,97344,97353,98202]
y: [0.00252525,0.00505051,0.00757576,0.010101,0.0126263,0.0151515,0.0176768,0.020202,0.0227273,0.0252525,0.0277778,0.030303,0.0328283,0.0353535,0.0378788,0.040404,0.0429293,0.0454545,0.0479798,0.0505051,0.0530303,0.0555556,0.0580808,0.0606061,0.0631313,0.0656566,0.0681818,0.0707071,0.0732323,0.0757576,0.0782828,0.0808081,0.0833333,0.0858586,0.0883838,0.0909091,0.0934343,0.0959596,0.0984848,0.10101,0.103535,0.106061,0.108586,0.111111,0.113636,0.116162,0.118687,0.121212,0.123737,0.126263,0.128788,0.131313,0.133838,0.136364,0.138889,0.141414,0.143939,0.146465,0.14899,0.151515,0.15404,0.156566,0.159091,0.161616,0.164141,0.166667,0.169192,0.171717,0.174242,0.176768,0.179293,0.181818,0.184343,0.186869,0.189394,0.191919,0.194444,0.19697,0.199495,0.20202,0.204545,0.207071,0.209596,0.212121,0.214646,0.217172,0.219697,0.222222,0.224747,0.227273,0.229798,0.232323,0.234848,0.237374,0.239899,0.242424,0.244949,0.247475,0.25,0.252525,0.255051,0.257576,0.260101,0.262626,0.265152,0.267677,0.270202,0.272727,0.275253,0.277778,0.280303,0.282828,0.285354,0.287879,0.290404,0.292929,0.295455,0.29798,0.300505,0.30303,0.305556,0.308081,0.310606,0.313131,0.315657,0.318182,0.320707,0.323232,0.325758,0.328283,0.330808,0.333333,0.335859,0.338384,0.340909,0.343434,0.34596,0.348485,0.35101,0.353535,0.356061,0.358586,0.361111,0.363636,0.366162,0.368687,0.371212,0.373737,0.376263,0.378788,0.381313,0.383838,0.386364,0.388889,0.391414,0.393939,0.396465,0.39899,0.401515,0.40404,0.406566,0.409091,0.411616,0.414141,0.416667,0.419192,0.421717,0.424242,0.426768,0.429293,0.431818,0.434343,0.436869,0.439394,0.441919,0.444444,0.44697,0.449495,0.45202,0.454545,0.457071,0.459596,0.462121,0.464646,0.467172,0.469697,0.472222,0.474747,0.477273,0.479798,0.482323,0.484848,0.487374,0.489899,0.492424,0.494949,0.497475,0.5,0.502525,0.505051,0.507576,0.510101,0.512626,0.515152,0.517677,0.520202,0.522727,0.525253,0.527778,0.530303,0.532828,0.535354,0.537879,0.540404,0.542929,0.545455,0.54798,0.550505,0.55303,0.555556,0.558081,0.560606,0.563131,0.565657,0.568182,0.570707,0.573232,0.575758,0.578283,0.580808,0.583333,0.585859,0.588384,0.590909,0.593434,0.59596,0.598485,0.60101,0.603535,0.606061,0.608586,0.611111,0.613636,0.616162,0.618687,0.621212,0.623737,0.626263,0.628788,0.631313,0.633838,0.636364,0.638889,0.641414,0.643939,0.646465,0.64899,0.651515,0.65404,0.656566,0.659091,0.661616,0.664141,0.666667,0.669192,0.671717,0.674242,0.676768,0.679293,0.681818,0.684343,0.686869,0.689394,0.691919,0.694444,0.69697,0.699495,0.70202,0.704545,0.707071,0.709596,0.712121,0.714646,0.717172,0.719697,0.722222,0.724747,0.727273,0.729798,0.732323,0.734848,0.737374,0.739899,0.742424,0.744949,0.747475,0.75,0.752525,0.755051,0.757576,0.760101,0.762626,0.765152,0.767677,0.770202,0.772727,0.775253,0.777778,0.780303,0.782828,0.785354,0.787879,0.790404,0.792929,0.795455,0.79798,0.800505,0.80303,0.805556,0.808081,0.810606,0.813131,0.815657,0.818182,0.820707,0.823232,0.825758,0.828283,0.830808,0.833333,0.835859,0.838384,0.840909,0.843434,0.84596,0.848485,0.85101,0.853535,0.856061,0.858586,0.861111,0.863636,0.866162,0.868687,0.871212,0.873737,0.876263,0.878788,0.881313,0.883838,0.886364,0.888889,0.891414,0.893939,0.896465,0.89899,0.901515,0.90404,0.906566,0.909091,0.911616,0.914141,0.916667,0.919192,0.921717,0.924242,0.926768,0.929293,0.931818,0.934343,0.936869,0.939394,0.941919,0.944444,0.94697,0.949495,0.95202,0.954545,0.957071,0.959596,0.962121,0.964646,0.967172,0.969697,0.972222,0.974747,0.977273,0.979798,0.982323,0.984848,0.987374,0.989899,0.992424,0.994949,0.997475,1]
layout:
title: "Large OP_RETURN sizes"
xaxis: { type: log, autorange: true, title: size }
yaxis:
title: "frequency"
- Total OP_RETURN data over the period was 473,815,552 bytes. So large OP_RETURNS accounted for 0.44% of usage by bytes, versus 0.0016% counting by transactions. (Only comparing to transactions with an OP_RETURN output)
- There were 34,283 txs burning sats to OP_RETURN outputs, for a total of 1,463,488 sats burnt. Largest burn was 931774:2482 with 69,630 sats burnt. Only one tx both burnt funds and had more than 83 bytes of OP_RETURN data, namely 930086:2470.
- I think there are 949,003 txs with between 43 and 83 bytes of OP_RETURN data, and 23,412,911 txs with OP_RETURN data of 42 bytes or less (ie compliant with the limit Knots used prior to its 29.2 release)