PDF markup meets AI takeoff — in your browser.

The unified AEC document workspace. Mark up drawings, measure to scale, run AI quantity takeoff, and collaborate live — without bouncing between desktop apps.

No credit card 60fps on 200MB drawing sets Free for 1 user, forever
vellum.app / projects / 102-river-east / A-201 — Floor 02 RCP Live
OFFICE 201OFFICE 202STORAGEOPEN OFFICE24′ - 6″RFI #042SarahMike

Inspector

RFI #042

Callout · Open

TradeElectrical
CSI div26 05 00
AssigneeM. Pirate
DueMay 12

AI takeoff

Rooms1294%
Doors2891%
Windows1986%
Sheet 4 of 142 · 1″ = 8′-0″ · meters internal3 collaborators · 47 markups · saved 2s ago

Built for the firms tired of paying $700/seat for a 2003 desktop app

GC NortheastMason & CoAtlas BuildVertex AECReed EstimatingHarborline BuildersIronwood AECSutter & VanceNorth Pier GroupCordell ConstructionGC NortheastMason & CoAtlas BuildVertex AECReed EstimatingHarborline BuildersIronwood AECSutter & VanceNorth Pier GroupCordell Construction

Design partner roster — joining the closed beta in May 2026

The whole pitch

One product, the strengths of two categories.

Legacy markup tools own annotation. AI estimators own takeoff. Vellum is the first product to do both, in a browser, on one canvas, with a single price tag.

CapabilityMarkup toolsAI estimatorsVellum
Web-native (no install, any device)
High-fidelity markup tools (13+ shapes)partial
Scale-aware measurements (length / area / count)
Real-time collaboration (live cursors + op-log)partial
AI-powered quantity takeoff
Sheet revisions with pixel + structured diffpartial
Per-seat pricing under $50/mo
Free tier for solo estimators

Vellum Studio

Real-time collaboration that feels like Figma — for blueprints.

Op-log architecture means every markup is an independent entity with a vector clock. Two estimators on the same sheet. No merge conflicts. No “last saved at 3:47” panic. Cursors stream over WebSocket; ops persist server-side; reconnect replays cleanly.

  • Live cursors with name labels and presence avatars
  • Op-log replays missed events on reconnect — no lost markups
  • Threaded comments with @-mentions on every markup
  • Per-user audit trail (who changed status, when, from where)
SMK
3 in this sheet · 12 markups today
S
Sarah LeeEstimator2m

Updated RFI #042 — moving the panel from W3 to W2.

M
Mike ParkPM1m

@sarah confirmed with electrical sub. Marking resolved.

K
Karim O.Fieldjust now

Photo pin attached on A-201 — panel is in. Looks good.

⚡ Op latency p95: 82ms · 0 dropped messages today
AI takeoff · Floor 2Claude Sonnet 4.6
12

Rooms

3 pending review

94%

avg confidence

28

Doors

5 pending review

91%

avg confidence

19

Windows

2 pending review

86%

avg confidence

47

Fixtures

9 pending review

82%

avg confidence

19

Pending

87

Accepted

6

Rejected

Total runtime: 47s · 4.2K tokens

AI takeoff

Run takeoff in 60 seconds.
Review what matters. Reject the noise.

We send each sheet through Claude Sonnet 4.6 with a structured tool-use prompt. Rooms, doors, windows, fixtures come back with bounding boxes and a calibrated confidence score. Every accept / reject becomes labeled training data for our Phase-2 detection models — the moat compounds with every project you run.

  • Detection types: rooms, doors, windows, fixtures (v1)
  • Calibrated confidence — never raw model output
  • One-click accept turns a detection into a real markup
  • p95 latency < 60s per sheet end-to-end

Sheet revisions

“What changed in Rev C?” — answered in 3 seconds.

Upload a new revision; we rasterize both pages at the same zoom, classify every pixel into add / remove / change, and overlay a per-page diff. Existing markups migrate forward automatically — no re-pinning RFIs every revision.

  • Pixel diff overlay with red/green/amber classification
  • Structured “what changed” list (vector path + text deltas)
  • Markup forward-migration with provenance trail
  • Side-by-side comparison mode for senior review
Rev B · Apr 12
RM 201RM 202OPEN
Rev C · Apr 28+12 −4
RM 201RM 202OPEN

60fps

Pan/zoom on 200MB drawing sets

<60s

p95 AI takeoff latency, per sheet

<100ms

Markup fan-out across collaborators

$24/seat

Pro tier — 1/30th of incumbent pricing

Pricing

Per-seat. No surprises. Cancel anytime.

Education and registered nonprofit firms get the Team tier free, forever.

Free

$0

For solo estimators learning the ropes.

  • 1 user
  • 3 active projects
  • AI takeoff: 5 sheets/mo
Start free
Most popular

Pro

$24/seat/mo

The standard plan most firms land on.

  • Unlimited projects
  • AI takeoff: unlimited
  • PDF/XLSX/JSON exports
Start 14-day trial

Team

$49/seat/mo

For multi-office firms with custom workflows.

  • SSO + audit log export
  • Custom report templates
  • Priority support
Talk to us

See the full feature matrix on the pricing page.

Bring a real PDF.
See the difference in five minutes.

Spin up an account, upload a drawing, run AI takeoff, export a markup report. No demo call required.