TL;DR: The four platforms measure aggregates inventory in different ways. Stockpile Reports is built around phone capture, pile by pile, across many sites. Propeller is built around survey-grade drone capture with its own ground control hardware. DroneDeploy is an all-in-one drone platform. Birdi (birdi.io) is a shared map that site, finance and operations all read from.
Key takeaways
- Phone accuracy depends on method. According to Stockpile Reports, an iPhone scan is accurate to within 5% of stockpile volume, and within 1.6% with safety cones as targets.
- Drone accuracy depends on ground control. According to Birdi's help center, its maps reach 2 to 4 cm vertical accuracy with RTK and well-distributed ground control points.
- Consistency matters as much as accuracy. According to Propeller, 20 measurements of one stockpile varied 2.3% on average, and 0.8% when boundaries were drawn tightly each time.
- The stakes are high per ton. According to the US Geological Survey, US crushed stone averaged $18.50 a ton in 2025.
- Pricing models differ completely. Stockpile Reports prices by piles under management, while Propeller, DroneDeploy team plans and Birdi Ultimate are quoted.
What is the difference between the four?
Each platform is built around a different way of measuring. Stockpile Reports measures piles from phones, drones or installed cameras and manages inventory by pile, product and site. Propeller builds survey-grade drone surfaces with its own ground control and PPK hardware. DroneDeploy is a broad drone platform for many industries. Birdi is a shared site map with volumes and tonnage.
So the right choice depends on how you count. A producer with hundreds of freestanding piles across many yards may want a phone in every manager's pocket. A quarry with a survey team and a busy pit leans to survey-grade drone data. Meanwhile, a business that runs drones across many job types may want one vendor for all of them. Every fact below was checked on October 7, 2026.
How do the four compare, row by row?
| Birdi | Stockpile Reports | Propeller | DroneDeploy | |
|---|---|---|---|---|
| Built around | A shared site map for the wider team | Phone-first stockpile inventory | Survey-grade drone capture for earthworks and mining | An all-in-one drone platform |
| Capture | Drone surveys you fly or bring in | Phone, drone or installed camera | Your drone, with AeroPoints and PPK | Drones, including docked; ground capture |
| Published accuracy | 2 to 4 cm vertical with RTK and 3 to 5 GCPs | Within 5% by iPhone; 1.6% with cones | About 3 cm with its PPK kit | Labels RTK or PPK without checkpoints "unvalidated accuracy" |
| Tonnage and densities | Material library and custom densities, Growth and Ultimate | Volume and tonnage on every report | Material properties for mass and value | Stockpile reports |
| Multi-site inventory | Sites within workspaces | Built for many sites and products | Unlimited sites | Projects across the organization |
| Access for people outside the paid team | Guests use no seat | Unlimited users on Business plans | View-only by default; 40 standard users | View-only map links; tools need a paid account |
| Data types in one view | Maps, point clouds, 360 photos, PDFs, DXF | Stockpile measurements and reports | Surveys, designs, point clouds, machine data | Maps, 3D models, 360 walks, video |
| Processing | Cloud | Cloud | Cloud | Cloud |
| Published price | Growth $287 USD a month, billed annually | From $100 a month for up to 10 piles | By quote | Flight & Analysis $4,188 a year; teams by quote |
| Where it is weakest | No phone capture; no design-surface volumes | Stockpiles only, not the whole site | Built around the survey team | Viewers pay to use tools |
How does Stockpile Reports compare with Propeller?
Stockpile Reports and Propeller suit different operations. Stockpile Reports puts measurement in the hands of whoever is at the pile, using a phone, and manages inventory by pile across many sites. Propeller gives a survey team survey-grade drone surfaces of the whole site, with ground control hardware, design comparison and machine data. One counts piles; the other surveys the site.
For a producer with many small yards and no survey team, Stockpile Reports' phone capture removes the need for a pilot at each site. In contrast, for a large quarry or mine with a survey team, Propeller's whole-site surface adds pit, haul road and design data the phone does not capture. Some operations would use both.
How does Stockpile Reports compare with DroneDeploy?
Stockpile Reports is a specialist inventory system, and DroneDeploy is a generalist drone platform with stockpile tools. Stockpile Reports prices by piles under management and includes unlimited users on Business plans. DroneDeploy covers aerial, interior and inspection work across industries, with team plans by quote. Choose Stockpile Reports for inventory focus, DroneDeploy for breadth.
DroneDeploy's breadth is its strength for organizations that fly for many purposes, with integrations to Esri, Autodesk and Procore. Stockpile Reports' focus is its strength for inventory: every report carries volume, tonnage, site, product and a confidence score. For aggregates inventory alone, the specialist is simpler.
Where does Birdi fit against the other three?
Birdi fits where the stockpile number has to reach people beyond the survey team, alongside the rest of the site record. It measures volumes and tonnage from drone surveys, compares surveys, and shares results with guests who use no paid seat. It does not measure by phone or calculate volume against a design surface.
What Birdi does in the count
AI Detect outlines stockpiles on a new map, and a person checks each outline. Assigning a material, from a built-in library or a custom density saved for the team, adds tonnage on Growth and Ultimate. The Base DEM method shows material added or removed since the last survey, and results export to CSV or PDF. For how Birdi compares with Propeller in more depth, see Birdi vs Propeller for mining.
What do users of each platform say?
Users of these platforms mostly praise ease of use, and their complaints are scattered rather than repeated. Propeller's reviews are strongly positive. DroneDeploy's complaints center on cost and on viewers needing paid accounts. Stockpile Reports' recent App Store reviews cluster around crashes in mid-2026, which its developer says an Apple update has since fixed.
Stockpile Reports
Its SR Measure app holds 3.8 from 48 ratings on the App Store. Of the 8 written reviews visible there, 4 from May and June 2026 report crashes or failed measurements on newer iPhones. On August 25, 2026, the developer replied that the cause was an Apple iOS 26.4 issue, fixed in iOS 26.6 with SR Measure 9.2.2. Older reviews range from "It seems to be accurate" (2021) to a pile measured at a quarter of its known size (2024).
Propeller
Propeller holds 4.8 from 20 reviews on Capterra, and 11 of the 20 praise its ease of use. Complaints are scattered: 3 mention interface friction and 2 processing time or crashes. One 2025 reviewer wrote, "All aspects of our company use the portal."
DroneDeploy
On Capterra, 7 of 9 reviews praise ease of use, especially flight planning. Cost appears in 2 of 9, plus 1 on the cost of view-only "analyst" users, and 2 say stakeholders need a paid account to use the tools. The pool is small and none of it is under three years old.
Birdi
Birdi has 5 reviews on Capterra, all rated 5, which is too few to show a pattern. The small complaints are bugs when switching between 2D, 3D and media views, and a wish for more drone-specific algorithms. We could not read Reddit or G2's full review pages for any of the four.
Which one should you choose?
Choose by how your operation counts stock. Many freestanding piles across many yards, measured often by site staff, point to Stockpile Reports. A survey-led quarry or mine with design and fleet data points to Propeller. Drones flown for many purposes point to DroneDeploy. A count shared with finance and operations alongside the site record points to Birdi.
Then test on your own piles. Measure the same piles with two methods, compare against a known quantity, and count how many people touch the number before it reaches finance. For the questions to ask any vendor, see our guide to choosing stockpile volume software.
Frequently asked questions
What is Stockpile Reports?
Stockpile Reports is stockpile inventory software for bulk materials, from EveryPoint. It measures piles from a phone, using its SR Measure app, or from drones and installed cameras. Each report gives volume, tonnage, site and product with a confidence score, and pricing is based on the number of piles under management.
Is phone stockpile measurement accurate?
According to Stockpile Reports, an iPhone scan is accurate to within 5% of stockpile volume, and within 1.6% with safety cones as targets. Independent research shows phone methods vary more by material than drones or laser scanners, so test on your own piles against a known quantity before relying on it.
Is Propeller better than DroneDeploy for aggregates?
Propeller is the stronger fit for survey-led quarries that want survey-grade surfaces, ground control hardware and machine data. DroneDeploy is the stronger fit for organizations that fly drones across many job types and want one platform. Both measure stockpiles; the difference is focus and who runs the workflow.
Which is best for many quarry sites?
For many sites with freestanding piles and no survey team, Stockpile Reports' phone capture and per-pile pricing scale simply. For many sites with drone programs, Propeller, DroneDeploy and Birdi all handle multiple sites. Decide whether site staff, pilots or surveyors will do the counting, then choose to match.
Can these tools give tonnage?
Yes. Stockpile Reports gives tonnage on every report, Propeller uses material properties for mass, DroneDeploy produces stockpile reports, and Birdi adds tonnage from a material library or custom density on Growth and Ultimate. In every case, tonnage depends on the density, so use one tested on your own material.
About the author
This comparison was written by the Birdi team. Birdi (birdi.io) is a geospatial AI workspace that quarry, mining and construction teams use to share drone surveys, volumes and site data in one map. We checked every product fact on each vendor's own site or help center on October 7, 2026, and counted the reviews ourselves.
Related reading
- Birdi vs Propeller for mining: the two platforms compared in depth.
- Four platforms compared: Propeller, DroneDeploy, Pix4D and Birdi.
- How to reconcile stockpile volumes: the month-end routine.
Sources
Statistics
- U.S. Geological Survey. "Stone (Crushed)." Mineral Commodity Summaries 2026. https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-stone-crushed.pdf
Vendor documentation (read October 7, 2026 unless stated)
- Stockpile Reports. Homepage, "Plans and Pricing" and "Stockpile Measurement FAQ." https://www.stockpilereports.com/faq/
- Birdi Help Center. "How accurate are my maps?" https://help.birdi.io/en/articles/13837409
- Birdi Help Center. "How to turn your stockpile AI Detect results into a volumetric report," "How to calculate stockpile tonnage in Birdi" and "How to compare stockpile volumes between two surveys in Birdi." https://help.birdi.io/en/articles/16590329
- Birdi. "Pricing." https://www.birdi.io/pricing
- Propeller. "Mining" and help center articles on stockpile consistency and the annual platform fee (2026). https://www.propelleraero.com/mining/
- DroneDeploy. "Pricing" and help center articles on stockpile reports and accuracy. https://www.dronedeploy.com/pricing
Reviews
- Apple App Store. SR Measure: 8 written reviews (2021 to August 2026) and rating (3.8 from 48), read October 7, 2026, with the developer's responses of August 25, 2026.
- Capterra. Propeller (20 reviews), DroneDeploy (9) and Birdi (5), counted September 2026. Reddit and G2's full review pages were not read.
