The overwhelming majority of criminal convictions in the United States are obtained through guilty pleas. To be constitutionally valid, guilty pleas must be knowing, voluntary, and intelligent. The information the defendant relies on to make a knowing, voluntary, and intelligent plea decision may be conveyed to the defendant through several modes, including but not limited to communication with defense counsel. Here, we address a mode that to our knowledge has previously not been systematically examined—tender-of-plea (ToP) forms. ToP forms are written instruments that inquire into whether the defendant understands and appreciates the plea decision and is capable of entering it. Using content analysis and comprehensibility measures, we examined a national sample of 208 tender-of-plea forms for both juvenile and adult defendants to determine what information they contained and their level of comprehensibility. The ToP forms were coded for several items concerning knowledge and voluntariness including rights waived, direct and collateral consequences, and capacity. Our findings show that the forms (a) are highly variable in their content, (b) exceed the reading comprehension of most defendants, and (c) are available more often to adult than to juvenile defendants. The implications of these findings are the forms should not be used to stand in place of “full and vigorous” judicial plea colloquies or meaningful defender-defendant discussions about plea decision-making.