There are tens, perhaps hundreds of sites that offer good charting options for stock price histories. However, I can’t find a single one that allows you to chart commodity prices with same customization, overlay, etc. capabilities - instead, there are crummy pre-generated charts with fixed parameters, or worse, just up-to-the-minute quotes.
Am I just looking in the wrong place, or what?
2 thoughts, one cynical, one practical
Practical: there isn’t enough of a consumer-level demand for this information, because most people can’t trade commodities (there may be SEC regulations on futures buying, IIRC) or are not interested in them (and rightfully so, imho). Ergo, there’s no competitive pressure to give this informaiton for free.
Cynical: because stock markets are over and done with in terms of absolute information transparency, commodities markets are the last bastion for market players to exploit information asymmetries.
Anyone can trade Futures. Can do it from home just like any daytrader if you want.
Futures tend to be more difficult though and dangerous as an investment not least because it is a zero-sum game. For every winner there is a loser on the other side of the trade (which is not true in the stock market).
Commodity pricing is very transparent. Indeed price discovery is one of the main purposes of a commodities market. It is when you get into derivatives that things get a lot more dicey for the investor.
Really big players do exploit asymmetries (which is where high speed trading comes in) but on the whole this does not hurt the average investor as it provides liquidity to the market.
If you really want to make your head explode try trading Options on Futures. 
Which is why I suggested that consumer investors not engage this market.
I’ll take your word for it, and possibly the markets don’t work this way (?) but I don’t get the sense that Joe the Plumber can sign onto some website and find the immediate (or 20-minute delayed) price of a Wheat future. Most of the commodity pricing I’ve seen online is end-of-day.
Just like the stock market Joe the Plumber needs to trade via a broker who is licensed to trade on the exchanges. The broker can (presumably) provide moment-to-moment pricing. Stock markets have delayed pricing too. They want you to pay for immediate pricing.
