MLS Photo Size Requirements, and How to Meet Them on a Mac

There is no national standard because there is no national MLS. Each board runs its own platform and publishes its own numbers. This table is what several of the large ones publish. Seven rows were opened on 9 October 2026, from the boards’ own sites and, for Stellar, from its training team’s course notes. Read your own board’s page, not this one.

Three things in that table are easy to get wrong. First, a cap can be written as “15 MB or 3000 × 2000”, and the page does not say whether a photo must meet both. Meet both. Second, Canopy says Matrix “saves all listing images at 2048 pixels wide x 1536 pixels tall, so this is the recommended minimum size”. It accepts up to 3000 × 3000, but nothing on the page says the extra pixels survive, so in our reading there is little reason to send more than that. Third, minimums are real: Realcomp accepts nothing below 512 × 340, and RANW sets 1024 × 768 as its own floor while noting that a photo must be larger than 330 × 220 to appear on Zillow.

Two names have no size numbers here. We found no public photo-size figures for Bright MLS or Realtor.com, so neither is in the table. What Bright does publish is a policy on images dated February 28, 2024, and it is about content: one exterior photograph within 72 hours of submission for most listings, an unbranded curbside view, and no identifiable person, readable text, contact information, sign or logo in a listing photo. Page dates matter too. Canopy’s article is stamped September 30, 2026 but carries a preview notice, and the CRMLS page shows both April 15, 2025 and August 2020 as update dates.

How to find your own board’s rule

• Search the board’s own help center for “photo requirements” or “photo specifications”, not a photographer’s blog. Blogs quote each other and disagree.
• Read the upload screen in your listing system, and the error text it gives when a photo is rejected. The message may name the limit you broke.
• Read the rules and regulations for the content rules. Stellar, for example, points its primary photo rule to Article 4.5.
• Ask your broker or the MLS support desk, and write the numbers on your shoot checklist once.

Resize first, then set quality. A 4032 × 3024 iPhone frame is about 12 million pixels. Fitting it inside 2000 pixels keeps about a quarter of them, and 1280 × 960 keeps about a tenth.

Quality 75 is Smol’s default and 80 is where we would start for interiors with smooth wall gradients. Those are starting points, not measured thresholds. The 125 KB case needs a check: sort the output by size and run the files that miss again at a lower quality. Smol also has a target-file-size mode (Neural) that takes any size from 4 to 4096 KB. It aims for a band rather than a hard ceiling, so a file can land over your cap, and it is slow, about 28 seconds for one 768 × 512 image. Keep it for the few photos that miss.

What shape should the photo be, and does DPI matter?

Shape decides the number you type. Stellar’s 1600 × 1200, NWMLS’s 1600 × 1200 public-search size and Canopy’s 2048 × 1536 are all 4:3, which is also the shape of an iPhone’s 4032 × 3024 frame. A 3000 × 2000 cap is 3:2. Smol fits the photo inside the maximum dimension on both sides, so a 4:3 frame set to 3000 comes out 3000 × 2250, over a 2000 pixel side. Set 2666 and it comes out 2666 × 2000. A 3:2 frame fits at 3000. Canopy adds that a photo not in 4:3 may be flagged as smaller than recommended because white space was added, and that such images “can be used without any issues or errors”.

DPI is not on the pages. RANW, Canopy, CRMLS, ARMLS and Realcomp each publish limits in bytes and pixels, and none states a DPI, so we would not spend time on the 72 versus 300 question. Canopy does say Matrix processes every image as sRGB. Count is a board rule too: NWMLS caps a listing at 40 photos and suggests 20 to 30, Canopy allows 48, CRMLS 75, and Stellar’s Picture Perfect notes give 100.

For scale: on 24 small Kodak test photos (high-quality JPEGs, default settings), Smol’s JPEGs came out 69.3% smaller, where ImageOptim’s default lossless pass saved 8.9% on the same files. Those test images are 768 × 512 film photographs, and Smol’s default 2000 pixel resize applies to a camera file, so a camera file will behave differently. The full method is on the benchmark page.

Not on any format list we opened. Three boards publish one: Canopy accepts only .jpg and .jpeg, and CRMLS and ARMLS each list the same ten extensions without HEIC. The other pages say nothing about HEIC, and a few help centers did not open for us, so a board may accept it. JPEG is the format every list has. Switch to it first.

You can stop the problem at the phone: Settings, Camera, Formats, Most Compatible makes new photos JPEG, per Apple’s own instructions. The cost is a larger file for the same picture, so you may prefer to leave the phone on High Efficiency and compress to JPG later. The background is in why iPhone photos are HEIC.

In Smol, use Compress with the output set to JPG, not Convert. Converting to JPG ignores the quality setting and writes a large, high-quality file, which is the opposite of what a 6 MB cap wants. Compress honors your quality and your maximum dimension in the same pass. The folder-at-a-time details are in batch converting HEIC to JPG and converting a single HEIC.

Do it once per shoot, not once per photo. Your photographer’s delivery folder or the iPhone export goes in whole; the output lands next to it.

1. 1

   Copy the delivery folder to your Mac

   Keep the originals untouched. Smol writes a copy with a _compressed suffix and never overwrites by default.

2. 2

   Drag the folder into Smol

   Mixed batches are fine: photos, floor plan PDFs and a clip can go in together.

3. 3

   Set output to JPG, quality 75 to 80

   Then set the maximum dimension to your board’s pixel cap from the settings table, allowing for the shape of your frames. Leave the fit mode on fit so nothing is cropped.

4. 4

   Run it and read the per-file sizes

   Smol shows the result for every file. Find the largest output. If it clears your cap, they all do.

5. 5

   Check one file for location data

   Open one output in Preview and choose Tools, Show Location Info. A stripped file has nothing to show.

6. 6

   Upload the compressed copies, exterior first

   Stellar’s Picture Perfect notes allow a water or aerial view first, with the front exterior second; otherwise lead with the front exterior. Bright wants an exterior photo within 72 hours of submission on most listings, and ARMLS requires a front exterior photo on a Residential listing. Put the exterior near the top and the rest in the order that sells the house.

Yes, for a narrower reason than it first seems. For an active listing the address is already public, so a coordinate adds little. The case that matters is every other use of the same files: photos texted to a buyer, posted to social before the address is public, or kept for a pre-market listing where the address is withheld on purpose.

What a phone writes is more than a pin. In our GPS measurements an iPhone photo can carry up to 15 GPS tags (14 on our test file): coordinates, altitude, a timestamp, speed, and the direction the camera faced. A sips resize left all 14 in place on our test file, and converting HEIC to JPEG carried the coordinates through on every route we tested, Smol’s Convert included.

Smol’s image defaults strip metadata, so the Compress path in the workflow above removes it unless you have switched that off. Check one output rather than assuming. If you only want the metadata gone without re-encoding anything, Smol also has Strip Metadata as its own operation; the folder version is batch-stripping a whole folder.

Two limits to be honest about. Coordinates in a file are not the only way a home gets located; the picture itself can, as covered in stripping EXIF is no longer enough. And the National Association of Realtors’ seller guide makes a related point plainly: “Everyone who enters your home during the sales process likely has a camera.” Your files are one part of that, not the whole.

The PDFs hit three kinds of limit: the MLS document slot, email, and the signing platform.

The Docusign figures come from its developer documentation, which was last modified in December 2024, so confirm the limit in your own account. Other transaction platforms set their own limits; we did not read any, so check yours inside the account.

Email is the one to plan for, because the receiving server counts the encoded message and encoding adds about 37%. Our email PDF guide lands on 18 MB for a 25 MB cap and 7 MB when you do not know the other side.

In Smol, Small is the email preset and Medium is the one for scans. Presets are pixel caps, not DPI targets, so a page’s effective resolution depends on its size. On a three-page, 300 PPI color test scan of an agreement, Medium came out at 109 PPI and Small at 82 PPI. Fed back to an OCR engine, Medium kept every word, Small 96.8% of them, and Tiny (55 PPI) 1.42%. Smol does not OCR. The chain that took that scan from 5,017,560 to 288,609 bytes (94.2% smaller) ran a separate free tool, OCRmyPDF, first and Smol’s Medium second, and the text stayed searchable; it is in compressing a scanned PDF without killing OCR. That is one test file. How much a PDF shrinks depends on how it was made, so check the output size every time.

Do not use Preview’s Reduce File Size on a text-heavy packet. It can enlarge the file; on a 21-page text-only contract it grew it by 111.8%. See why Preview’s Reduce File Size can enlarge PDFs. And compress before anything is signed: a digital signature covers the exact bytes, so rewriting the file afterward invalidates it. Some generators, ReportLab among them, produce PDFs that barely shrink at all.

Walkthrough video

For the MLS, it may not be a problem, because some boards do not hold the file. ARMLS takes video as an “embedded code” and virtual tours as a link. Bright’s policy of February 28, 2024 says “The MLS hosts only links to virtual tours, which are hosted by the Subscriber’s service provider.” Check whether your MLS hosts video at all; where it does not, the video lives with whoever you pay to host it.

Compression matters for the other places the clip goes: the email to a seller, the text to a buyer, the file you send to a stager. Aim at 15 MB, export H.264 in an MP4 because you do not control the recipient’s player, and check the output size. Smol has no size target for video: its controls are codec, quality and output width. On longer clips, lower the output width or the quality setting and run it again. The arithmetic: one minute at 15 MB leaves about 1,904 kbps for the video after 96 kbps of audio, a budget worked out in that guide rather than a Smol setting. Past about two minutes, send a link instead; the reasoning and the numbers are in how to compress a video small enough to email. A walkthrough shot by a video team has its own delivery problem, covered on the video production page.

The TinyPNG limits are from TinyPNG’s own page (read 9 October 2026). The next section covers what an upload means for listing documents. See also our Smol versus TinyPNG comparison and the head-to-head test against ImageOptim.

For a public listing photo, the upload risk is small, since the picture is about to be displayed everywhere. Seller disclosures, inspection reports and signed purchase agreements are different files. They can carry the owner’s name and the property address, and an online compressor works by receiving your file on its server. That is a decision about who else holds the file, and your brokerage’s policy may have an answer before you do.

Smol processes files on your Mac and uploads nothing; there is no account and no server in the loop. Its image defaults strip metadata, and stripping metadata from a PDF is its own operation. That is a fact about where the work happens. It is not a claim about any law or rule, and it is not redaction: Smol does not black anything out, and a stripped PDF has been shown to be reversible with a free tool unless the file is rewritten afterward, as shown in removing metadata from a PDF. See the confidential documents page for the wider picture.

Smol is $29 once for one Mac. Team is $49 once for three Macs, and Enterprise is $20 a seat for 5 to 500 seats, managed from one dashboard. A small team with a transaction coordinator and two agents fits Team. A brokerage uses Enterprise. There is no subscription and no per-file cap.

The point of having it in an office is consistency. Presets are saved on each Mac, so write your board’s photo settings and your PDF-for-email preset on one page and have each agent recreate the preset on their own Mac. The Finder Quick Action in add a compress Quick Action to Finder puts it on a right-click. A watched folder can compress each shoot as it lands, but it can make already-optimized files larger, so point it only at a folder of fresh camera exports; the caveat is in the watched folder guide. Marketing staff who handle the same files for brochures will find the marketing teams page useful.

Your photographer already delivers to spec. If the delivery includes a web-sized JPEG set under your board’s cap, you have nothing to compress. Check the folder before you build a routine around a problem you may not have. If you are the photographer, that page is the one for you.

You need to redact. Smol does not redact, edit, sign, merge or split PDFs, and it does not OCR. Blacking out a Social Security number in a disclosure is a different tool. Removing PDF metadata is not redaction either, and the result has been shown to be reversible with a free tool unless the file is rewritten afterward.

You need pixel-identical output. Smol always re-encodes images; there is no lossless mode. For a lossless pass, ImageOptim is the answer, and the head-to-head test shows what it saves.

You are not on a Mac. Smol runs on macOS only, so a Windows office desktop or an iPhone alone cannot run it. Use the phone settings above, or the MLS’s own resize.

You compress a photo once a month. Preview does a single image well and costs nothing. Smol pays off when a shoot is dozens of files, or when the PDFs and video arrive with it.