Flatproof vs Threadline
Flatproof
flatproof.appThreadline
usethreadline.comSide by side
| Figure | Flatproof | Threadline |
|---|---|---|
| Price from | $5/mo | $199/mo |
| Free plan | Yes | — |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| Plans published | 3 | 1 |
| Spec score · Design Proofing Software | 8.1 (#11) | 7.4 (#24) |
| Security | Flatproof says it uses access controls, signed upload and download flows, rate limits on sensitive endpoints, encryption where appropriate, and production security headers. | Threadline says it uses HTTPS/TLS in transit and restricted access controls, does not sell customer data, and allows artwork, mockups, and proof records to be exported. |
| Support | Refund requests are handled by emailing support from the address associated with the Flatproof account. | Users can contact the Threadline team from a workspace page or email Jon at [email protected]. |
Plans
In their own words
Flatproof
Flatproof is web-based proofing software for client approvals. It handles images, PDFs, videos, audio, live websites, Figma links, presentations, and other uploaded files. A user can upload or import a proof, share one link, gather comments, manage versions, and record approvals. Clients and reviewers can comment and approve through that link without becoming paid seats. Annotation tools, approval workflow, version history, and guest reviewers are included. AI review inspects selected areas and creates private draft suggestions that the user may turn into feedback. Google Drive and Figma integrations are shown for importing source files or frames. Flatproof has a free plan with 200MB storage and 25MB uploads, plus unlimited creators and reviewers. Solo costs $5 a month with 100GB storage; Studio costs $29 a month with 1TB storage and bring-your-own AI key. The product is in beta, so bugs and interruptions may occur.
Threadline
Threadline has no write-up on Specifiction yet; its figures are above.