Write Resale Listings with ChatGPT: eBay, Vinted, Marketplace and Poshmark

Why this is worth 10 minutes

The slow part of selling isn’t taking the photo. It’s the writing: a title buyers will actually search for, a description that answers questions before they’re asked, every flaw listed, measurements in the right order, then the same “is this still available?” message ten times. ChatGPT is good at exactly that kind of writing. You stay in charge of the facts: what the item really is, what shape it’s in, and what it’s worth.

What each site asks for (checked Oct 24, 2026)

• eBay. Photos: at least 1, at least 500 pixels on the longest side (eBay recommends about 1600 x 1600), up to 24. No stock photos for used, damaged or defective items; no added borders, text or watermarks. Listing: pick the condition that matches (the options change by category), show close-ups of any flaws, and add a coin or ruler if the size isn’t clear.
• Vinted. Photos: up to 20. First photo shows the whole item, no collages. Your own photos only, no stock or watermarked pictures. Natural daylight, no flash or filters. Listing: a specific title (brand, color, type, features, not “very nice dress”), plus measurements, materials, alterations, missing parts and every flaw. Choose the true condition; if unsure, pick the lower one.
• Facebook Marketplace. Photos: Marketplace → Create new listing → Item for sale → Add photos. Listing: fill in the details the form asks for and keep chats in Facebook or Messenger. Purchase Protection covers eligible orders with shipping or checkout, not local pickups.
• Poshmark. Photos: up to 16 photos and 1 video (per Poshmark’s listing guide); make your Covershot (first photo) well lit and clear. Listing: a title with brand, category and defining features; fabric, sizing, measurements and condition in the description. The form shows what you’ll earn after fees when you enter a price.

Step 1: Take honest photos (5 minutes)

1. Clean, plain background. eBay suggests an uncluttered space and a neutral backdrop; white is usually best, but a darker background can work better for shiny things like jewelry. Poshmark suggests a white wall, crisp fabric or a simple tabletop.
2. Good light, no flash. Vinted says natural daylight beats lamplight and to skip flash and filters. eBay says avoiding flash and overhead lighting cuts glare.
3. Main photo = the whole item, face-on. Then other angles, the label or model tag, and a clear close-up of every flaw (eBay and Vinted both ask for this).
4. Size not obvious? eBay suggests a photo with a coin or ruler next to the item.

Step 2: Measure and confirm the facts yourself

ChatGPT can read a label in a photo and suggest which measurements buyers want, but it can’t measure your item. OpenAI says images are resized before ChatGPT looks at them, that it struggles with precise spatial tasks, and that it may describe things incorrectly. So:

• Grab a tape measure. Lay clothes flat. Ask ChatGPT which numbers matter for your item (prompt #1 below does this), then measure them yourself and type them in.
• Look up the model number on the maker’s own website for things like electronics, tools and car parts, and copy the official dimensions and specs. Vinted asks electronics sellers for the brand, model, features like storage or screen size, plug type, included accessories and anything that doesn’t work.
• Don’t let it guess the brand or the era. If ChatGPT isn’t sure, it should say [CHECK]. You confirm it from the label, tag or receipt.

3 copy-paste prompts to try today

1. 🏷️ Photos → title + honest description

I'm selling this item on [EBAY / VINTED / FACEBOOK
MARKETPLACE / POSHMARK]. Photos attached (front, label,
flaws).
Write:
1. A title with the words a buyer would search for:
   brand, item type, model or style, size, color, key
   feature. No filler words like "nice" or "wow".
2. A short, honest description: what it is, condition in
   plain words, every flaw I can see in the photos, and
   what's included.
3. A list of the exact measurements a buyer will want for
   this kind of item, with blanks like [__ in] for me to
   fill in. Don't estimate measurements from the photo.
If you can't tell the brand, model, size, material or age
for sure, write [CHECK] instead of guessing.

2. 💲 Organize my sold comps into a fair price

I'm pricing a [ITEM, BRAND, MODEL/SIZE, CONDITION].
Here are SOLD listings I found myself (price, shipping,
condition, date sold):
[PASTE 3 TO 10 SOLD LISTINGS]
Please:
- Drop any that aren't a close match and tell me why.
- Give me the low, typical and high sold price, counting
  shipping.
- Suggest a list price and a lowest offer I could accept,
  based only on these sales.
Don't invent prices that aren't in my list.

Where to find sold comps: on eBay, search for your item and filter the results to sold (completed) listings. eBay says those results cover listings that sold in about the last 90 days, while Product research in Seller Hub covers up to 3 years of sales, including the real price when a Best Offer was accepted. ChatGPT only sorts what you give it; you’re the one checking real sales.

3. 💬 Friendly buyer replies + a scam check

Write short, friendly replies I can copy for these buyer
messages about my [ITEM] listed at [$]:
1) "Is this still available?"
2) A lowball offer of [$]. My lowest is [$].
3) "Can you hold it until Friday?"
4) [PASTE ANY MESSAGE THAT FEELS ODD]
For #4, also tell me if it shows any of these warning
signs: wants to talk off the app, says they overpaid or
paid twice, sends a payment screenshot, offers a check
for more than my price, asks for a verification code, or
wants to pay with a gift card. Keep every reply polite.

You send the replies, not ChatGPT. If a message hits a warning sign, stop and read the scam section below before you answer.

Holiday selling 2026 (checked Nov 3)

Clearing out closets and the garage before the holidays? Black Friday is Friday, November 27 and Cyber Monday is Monday, November 30 this year, so list in early to mid November while gift shoppers are browsing. What each site offers right now, from its own pages:

• Mercari. Buyer-paid shipping is free on eligible orders of $50 or more from October 22, 2026 to January 4, 2027, automatically, with no code. A single item qualifies when it ships with a Best Rate label of 5 lb or less (package up to 1 cubic foot, longest side 22 inches or less); bundles from the same seller qualify at $50+ and 5 lb or less combined. Mercari tells sellers to add package dimensions and switch eligible listings to buyer-paid shipping so buyers get the free shipping.
• Vinted. When you lower an item’s price, Vinted says members who favorited it can get a notification that the price was reduced. So a price drop on a well-liked item reaches people who already want it.
• Poshmark. Offer to Likers sends a private offer to everyone who liked a listing: tap Offer/Price Drop, choose Offer to Likers, drop the price at least 10% and pick a shipping discount. Poshmark says offers expire in 24 hours and must be at least 10% below your lowest offer in the last 90 days to be sent.
• Shipping gifts by December 25? USPS’s 2026 recommended send-by dates for the lower 48 are Dec. 17 for Ground Advantage, Dec. 18 for Priority Mail and Dec. 19 for Priority Mail Express. Put your own last ship date in your listings or shop announcement so buyers know.

4. 🎁 Plan my holiday sale from my liked items

Help me plan a holiday sale for my [EBAY / VINTED /
MERCARI / POSHMARK] listings. Here are my items with the
CURRENT listed price, how long each has been listed, and
how many likes or favorites each has:
[PASTE YOUR LIST]
My lowest acceptable price for each: [PASTE]
Please:
- Sort them: most-liked first, then the oldest listings.
- For each, suggest a holiday price at or above my lowest
  price, and say whether to drop the price or send a
  private offer to likers.
- Group small items that could ship together as a bundle.
- Write one short, honest shop announcement with my last
  ship date: [DATE].
Use only the numbers I gave you. Don't invent prices,
fees or shipping costs, and never suggest raising a price
first so the discount looks bigger.

Step 3: Pick the condition honestly

The condition label is where most returns start. eBay says choosing the correct item condition is part of its selling practices policy, and the options change by category (a “Used” item should come with a description of any imperfections). Vinted’s scale runs New, Like new, Very good, Good and Satisfactory (plus Needs repair for electronics), and it says if you’re unsure, pick the lower one. On Facebook Marketplace, eligible checkout orders can be refunded if the item arrives different than described, including when the condition isn’t accurate. Ask ChatGPT to describe the flaws plainly, then you choose the label.

Buyer scam red flags (from the FTC and Facebook)

Privacy for sellers

• Vinted suggests leaving your face out of photos (a hanger, mannequin or flat lay works) and not sharing full names, addresses, phone numbers or bank details in chats.
• Before you upload a photo to ChatGPT, crop out mail with your address, family photos and anything with your name on it.

Troubleshooting

• It guessed the brand wrong. Upload a sharp close-up of the label and say: “Read the label exactly as written. If you can’t read it, say so.”
• The title is too long for the site. Say: “Shorten this to fit [SITE]’s title limit. Keep brand, item type, size and color.”
• It sounds like an ad. Say: “Make it plain and factual, like a neighbor describing it. No hype words.”
• It gave me a price out of thin air. Ignore it. Use prompt #2 with real sold listings you found.
• Upload limit reached. OpenAI says Free users can upload 3 files a day. Put your best 1 or 2 photos in, or type the label details instead.

New to uploading? Our how to upload a photo or PDF to ChatGPT guide shows how. Thinking about turning reselling into a side income? Read how to make money with ChatGPT (the honest version). Want to keep your inventory in a spreadsheet? See ChatGPT for Excel and Google Sheets. More reseller prompts: AI for thrift shoppers and resellers.

Why Bot Club is only $9 a month

This guide gives you the first three listing prompts free. Bot Club is for skipping the trial and error: the 12 extra reseller prompts (10-item batches, how to measure, honest flaw wording, cross-posting, “why isn’t this selling?”, bundle offers, shipping and return replies, price-drop plan, inventory and profit table, thrift-store checklist) and the fill-in listing card above, plus every other members-only pack (emails, quotes, spreadsheets, paperwork, social posts, picture prompts and more) in one Member Library, and a new recipe each month. One extra sale can cover it. Cancel anytime from your Stripe receipt.

Want it done faster?

Not sure which assistant fits you? Take the 2-minute AI sidekick quiz.

Buying gifts this season? The same “check the real price” habit helps when you shop, too; see holiday shopping with ChatGPT for a gift budget and a before-you-pay deal check.

Selling a lot online? IRS.gov says that in 2027, people paid over $20,000 in more than 200 transactions in 2026 through online marketplaces or payment apps will get a Form 1099-K, and all sales income must be reported either way. Organize your sales records with Get your tax papers ready with ChatGPT.

Selling from a small shop, not just online? See Small Business Saturday 2026 with ChatGPT for a simple plan, honest posts and signs for your shop.

Sources

• OpenAI Help Center: ChatGPT Image Inputs FAQ (checked Oct 24, 2026)
• OpenAI Help Center: Uploading files and audio to ChatGPT (checked Oct 24, 2026)
• eBay: Picture policy (checked Oct 24, 2026)
• eBay: Adding pictures to your listings (checked Oct 24, 2026)
• eBay: Item condition by category (checked Oct 24, 2026)
• eBay: Product research (checked Oct 24, 2026)
• Vinted: What photos you should upload (checked Oct 24, 2026)
• Vinted: Describing an item (checked Oct 24, 2026)
• Vinted: Choosing item condition (checked Oct 24, 2026)
• Vinted: Uploading step by step (checked Oct 24, 2026)
• Poshmark: Listing on Poshmark (checked Oct 24, 2026)
• Poshmark: Tips for how to make your first sale (checked Oct 24, 2026)
• Facebook Help Center: Sell something on Facebook Marketplace (checked Oct 24, 2026)
• Facebook Help Center: About scams on Facebook Marketplace (checked Oct 24, 2026)
• Facebook Help Center: How Purchase Protection works on Facebook Marketplace (checked Oct 24, 2026)
• FTC Consumer Advice: Selling stuff online? Here’s how to avoid a scam (checked Oct 24, 2026)
• Mercari: Free shipping on orders $50+ (Oct 22, 2026 to Jan 4, 2027) (checked Nov 3, 2026)
• Vinted: Managing your notifications (checked Nov 3, 2026)
• Poshmark: Your complete guide to Poshmark’s features and tools (Offer to Likers) (checked Nov 3, 2026)
• USPS: 2026 Holiday Shipping Deadlines (checked Nov 3, 2026)
• FTC Guides Against Deceptive Pricing, 16 CFR 233.1: Former price comparisons (checked Nov 3, 2026)