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ProStamp alternative for teams: LockProof vs. ProStamp
What is the actual difference between LockProof and ProStamp?
They are two different shapes, not two versions of the same thing. ProStamp is an app on the worker's own phone, and the worker chooses when to capture. LockProof runs the other direction for a job on your schedule: your system sends a link, the record is already open on the server, and the worker taps through with no app and no account. Proof camera in one pocket, or a dispatch loop across a crew.
Is ProStamp a good choice?
For a solo pro or small crew who wants a personal proof camera on their own phone, at a consumer price, genuinely yes. At a few dollars a month it captures with trusted time, GPS, street address and tamper-evident signatures, bundles a job into a reusable checklist, and publishes a verifier anyone can drop a file into without an account. If you are one person documenting your own work, that is a lot of product for the money.
What does ProStamp cost compared to LockProof?
ProStamp Pro is $4.99 a month, or $49.99 a year, with Team Workspace listed as a separate business product for invited company teams. LockProof is $99 a month on Essentials, with Professional from $399 a month, sized to the sites and workers you run rather than sold as an individual seat. Those are different shapes, so the two numbers do not compare line for line — match the shape to the operation you need to cover.
What does a photo verifier actually establish?
ProStamp answers this on its own verifier page, and the answer is worth reading before you buy anything in this category. Its top result “proves upload provenance and byte integrity; device attestation is a separate future level.” Integrity and origin are separate questions, and origin is the one LockProof answers structurally on the dispatched path.
Can a worker use LockProof without installing anything?
Yes. The submit flow authenticates the link, not a user — there is no account for a worker to create and nothing to install, so the capture runs in the phone's browser. That is the practical difference when you are covering a crew, contractors or a vendor whose phones you do not control.
Two different shapes
ProStamp’s own headline for the product:
“Verifiable proof photos for work that happens on site.”
Our summary of what it does, compiled from their pages rather than quoted: A proof camera for on-site work. The app captures photos with trusted time, GPS, street address and tamper-evident signatures, and a cryptographic signature seals each photo so image changes are detectable. Personal Jobs bundle a work plan, proof photos, client confirmation and a shareable final report; Team Workspace adds role-based access, a durable upload queue and a manager review portal.
Its use-cases are ours almost exactly. Named on the site: cleaning and janitorial, property management, maintenance and repairs, field service.
So the difference is not the sealing. Both products seal a capture so later changes are detectable, and ProStamp uses the same careful word for it that we do. The difference is where the record starts. In a camera app the worker downloads it, opens a job, and shoots. In LockProof, for a job you put on the schedule, your system sends the link and a row for that send already exists on the server before the worker taps anything — so the photo arrives into a record you created rather than one that begins on a phone.
The seam at the verifier
ProStamp’s verifier returns one of three results, under the heading “Three trust levels, plainly explained.” It describes each one:
Team server receipt. “The file matches a ProStamp server signature issued after an authenticated Team upload. It proves upload provenance and byte integrity; device attestation is a separate future level.”
Legacy integrity. “The media and embedded fields are internally consistent with the legacy HMAC. Because its key shipped in the app, this does not independently authenticate origin.”
Changed or unknown — No trusted conclusion. “The file may differ from its labeled bytes, lack usable metadata, or have no valid Team server receipt.”
Elsewhere on the same page they put the same point in one sentence:
“A standalone legacy JPEG can still be checked for internal consistency, but its shared client key is not independent proof that an authentic app captured it.”
The three results and the sentence above are quoted from prostamp.app/verify, as of August 11, 2026.
That distinction is worth carrying into any purchase in this category, and we walk through it at length in what a photo verification code checks. Integrity asks whether a file changed. Origin asks who captured it, of what, and on whose instruction. LockProof answers the second one structurally on the dispatched path, because the job existed in your account before the camera opened.
Six comparisons, in prose
Who starts the record. With ProStamp the worker does, when they choose to capture. With LockProof, for a scheduled job, your system does — the link goes out and the row exists before the worker taps.
What the worker needs. The worker downloads the ProStamp app to their own phone and chooses when to capture. A LockProof worker needs a link: the submit flow authenticates the link rather than a user, so there is nothing to install and no account to create.
Pricing shape. ProStamp publishes a flat subscription price and lists Team Workspace separately as a business product for invited company teams. LockProof is priced for an operation rather than for an individual, sized to the sites and workers you run. The figures are in the pricing question above; the point here is that they are not the same kind of number.
What an outsider opens. A public verifier at prostamp.app/verify takes a ProStamp JPEG or an Evidence Pack ZIP with no account, and “uploaded files are processed only to verify the signature and are not stored.” A LockProof proof link is signed rather than public: you send it, it opens with no account, and it expires after seven days.
Dispute handover. ProStamp’s verifier page recommends its Evidence Pack here: “For disputes, client approvals, inspections, or team handoff, share an Evidence Pack instead of screenshots or chat-compressed photos.” LockProof’s equivalent is an expiring, revocable share link, on Professional and up.
Closing out a job. Personal Jobs bundle a reusable checklist template, an optional client acknowledgment, and a completion report; the client can respond to a private seven-day review link from their phone without the app. LockProof’s equivalent unit is the scheduled job itself, and the dashboard reads done, late or missed across every site.
ProStamp facts throughout are from ProStamp’s own site (opens prostamp.app) and its verifier page, as of August 11, 2026. Every ProStamp statement anywhere on this page is something the vendor publishes about itself.
When ProStamp is the right call
A solo contractor, a one-van operation, an inspector documenting their own visits: buy ProStamp. At $4.99 a month, or $49.99 a year, it is a proof camera in your pocket for less than a site-level plan costs, you control every capture, and the public verifier means a client or an adjuster can check a file without an account. On its optional client acknowledgment, their page says: “Client acknowledgment records a response to the shared work summary; it does not verify identity and is not a notarization or contract-grade electronic-signature service.”
The shape stops fitting when you are not the one holding the phone. Covering a crew, a cleaning contractor or a vendor means getting an app onto phones you do not control and keeping it there. That is the point where a dispatch loop earns its price: the schedule sends the request, and the record exists on your side whether or not anyone opened anything.
What LockProof does not settle
A sealed record proves a live capture through the camera and its integrity since sealing. It does not grade the work, and it does not certify that the scene in the frame is the scene on the work order. Somebody still has to look. That is a narrower claim than the phrase “photo proof” suggests on its own, and we would rather say so here than have you find out during a dispute. If you want the mechanism rather than the pitch, keeping dispute-ready vendor records walks through what actually ends up in the file.