The Best AI Tool for Product Copy

July 3, 2025

Notes from the intersection of branding, copywriting, and AI.

The copy describing your products might as well be great

Between ChatPGT 4.5 and Claude Sonnet 4, which AI model writes the best product copy? The quick answer: It sure looks like Claude is the winner, at least in early June 2025. But let’s take a close look.

Original Product Copy

I grabbed some product copy for a hooded bike jersey and asked both ChatGPT and Claude to rewrite it using various brand attributes. I’ll discuss one of the brand attributes in this post. Here’s the original product copy:

“Cooler months can put a lot of demand on your gear closet, so the Men's Summit Hooded Thermal Jersey was designed with versatility in mind. Wear it as a warm-yet-breathable outer-layer during fall and spring rides and use it as your insulating mid-layer when the mercury plummets during the winter. The technical fleece is constructed with a grid fabric that allows it to quickly transfer moisture while retaining heat to keep you focused on the ride, not the thermometer. The Summit Hooded Thermal Jersey features two zippered hand pockets, a zippered chest pocket, and a hood that's slim enough to fit under a helmet for really chilly rides.”

This is the average sort of product copy you’ll find in most web catalogs. It’s too focused on features—the only benefit seems to be that it’ll “keep you more focused on ride”—and while it speaks to the customer a bit (you/your), it’s not nearly as engaging as it could be. What’s more, if the benefit is improved focus, the copy doesn’t play that out with other words like concentration, better attention, up-shifting, or locking in. 

ChatGPT Rewrite

First I asked ChatGPT to rewrite the copy. I used this simple prompt: “How would you rewrite this product copy if one of the brand attributes was “reliable"?

Here’s what I got back:

“Cooler months put extra demands on your gear, so the Men's Summit Hooded Thermal Jersey was built to reliably handle it all, ride after ride. Designed for versatile performance, it's your dependable outer layer during crisp fall and spring outings, and becomes a trusted insulating mid-layer when temperatures drop in winter. Its technical fleece features a structured grid fabric that reliably transfers moisture and retains heat, keeping you comfortably focused on your ride, not the weather. With two secure zippered hand pockets, a zippered chest pocket, and a streamlined hood that reliably fits under your helmet, this jersey ensures you're consistently equipped for the coldest adventures.”

The ChatGPT version gives a lot more emphasis to the customer. Using “you” and “your” constructions has been shown to improve purchase outcomes. However, there’s too much “your gear,” “your ride,” “your helmet,” and not enough “keeping you focused.” So while there’s a lot of “you” in there, it’s not deployed as well as it could be. Plus, what’s “comfortably focused” mean? Get too “comfortably focused” and you could end up taking a header.

Next, you can see how Claude went all-in on the concept of “reliable.” To a fault, I’d say, which is why you’d still want to edit. Three instances of the word “reliably” does not excellent product copy make. But unlike the original, it does play out the concept of “reliable” with words like dependable, trusted, and ride after ride. So this version has more emphasis on benefits, though it still suffers from more features than benefits. As a rider with this hooded jersey you’ll be more focused and you’ll be equipped. Is that enough?

Claude Rewrite

Okay, so how did Claude do with the same original product copy and prompt? Here’s its rewrite:

“When the temperature drops, you need gear you can count on. The Men's Summit Hooded Thermal Jersey delivers consistent performance ride after ride, season after season. This dependable layer adapts to changing conditions—providing reliable warmth and breathability as an outer layer during fall and spring, then seamlessly transitioning to trusted insulation when winter hits hard.

The proven technical fleece construction features a grid fabric that consistently transfers moisture while locking in heat, so you can rely on steady comfort no matter what the thermometer says. Built to perform when it matters most, the Summit features thoughtfully designed storage—two zippered hand pockets, a zippered chest pocket, and a low-profile hood that fits reliably under your helmet for those brutal cold rides.

Your go-to thermal layer that won't let you down.”

Claude generated more words. That’s probably a good thing in this instance. Rule of thumb is that product copy should be 100-350 words, so Claude’s rewrite is actually on the short side at 131 words. Some say that as long as it’s engaging, it doesn’t matter how long it is. The theory being, longer is better for SEO, and longer doesn’t matter for someone who’s actively shopping and ready to invest money. 

Next, Claude produced the same number of you/your phrases. This includes two instances in the first sentence, which, by the way, was much better than ChatGPT’s first sentence. In cold weather, “needing gear you can count on” (Claude) is much better than “it puts extra demands on your gear.” I don’t want to know how the weather affects my gear, I want to know I can count on my gear in cold weather. Claude also deployed its use of “yous” more effectively—you can count on, you need, won’t let you down, you can rely on.

What about how Claude dealt with the brand attribute “reliable”? It used three variations on the word, which is probably one too many, but at least it didn’t repeat the same word three times, as ChatGPT did. Claude also did a much better job baking the concept of reliable into the copy with words like consistent performance, ride after ride, season after season, dependable, trusted, proven, steady, and won’t let you down. So in Claude’s version, the brand benefit “reliable” aligned with the product benefit. I especially liked the notion that this thermal layer won’t let me down. 

In this case, Claude comes out the clear winner. I’ll experiment with other brand attributes in the future and see how each of these models performs. I’ll be eager to see if it’s always Claude or if Claude just nailed “reliable.” One caveat: Everything could change when the next round of models are released.

The Power of Brand Attributes

In addition to the ChatGPT vs Claude evaluation of product copy, this is an excellent example of how powerful a brand attribute can be. If the word “reliable” can make that much difference, imagine how powerful your brand and product copy would with a carefully defined purpose, archetype, set of values, and attributes? Interested? Talk to us about Brand Gravity.