On-device Analysiswith no AI

F4 on a MacBook displaying an engineering drawing with GD&T annotations

The Only On-Device Platform for 2D + 3D PMI Validation

Advanced PMI validation and analysis directly from the most popular design file formats

See your part like never before

Explore a real engineering drawing alongside its CAD model. Toggle individual datum reference frames to see exactly how each one constrains the part in 3D, making complex GD&T relationships intuitive and easy to understand.

Drawing

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CAD Model

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Choose demo part

Download ASME Y14.5-2018 FIGURE 7-4 source files

F4 labeling datums, feature control frames, dimensions, and annotations on an engineering drawing

Instant Annotation

F4 can read and annotate your drawing with incredible accuracy. It identifies:

Datums & Datum Targets
Feature Control Frames
Dimensions & Thread Callouts
Custom Flagnotes & Annotations

All done in seconds, and with models that run fully on-device.

Building The Unified Part Model

F4 is the only software that can transform PDF and STEP files into a unified and shareable part model.

With the full context of 2D and 3D data, F4 enables validation and analysis work that was previously impossible in most design workflows.

Validate PMI Against the Standard

No more guesswork. Our software is tied to the ASME Y14.5 Standard.

Catching the Bad GD&T

We check for hundreds of unique errors across all of your datums, controls, and dimensions, ensuring your GD&T is interpretable and meaningful.

Incorrect application of geometric controls
Redundant or incomplete definitions
Erroneous datum and datum reference frames
Inappropriate tolerance refinements
Incorrect or missing syntax

F4 flagging an invalid position tolerance and suggesting the correct diameter modifier

F4 flagging an invalid parallelism tolerance in the GD&T inspector

Coming Soon

Design Rule Checks

Apply custom design rules to your PMI.

Upscale your DFM and DFI flows by adding custom rulesets and running comprehensive checks across your features — letting you put the focus back on design intent.

Accelerate your Analysis Workflows

Compute single-part stackups in just two clicks.

Interface Stackups

Single-Part Stackups can be computed in only two clicks, accounting for:

Datum Shift
Bonus Tolerances
MMC/LMC States

Stepped cylindrical part model used for a single-part stackup

Stackup Breakdown

Contribution rows, subtotal, and final answer for the selected requirement.

Description	Type	Min dist	Max dist	Tol
Radius FOS	Radius	-39.75	-39.55	0.2
Geometric Tolerance	⌖	-0.05	+0.05	0.1
Bonus Tolerance	Bonus	+0	+0.2	0.2
Datum Shift	Shift	+0	+0	0
Basic Dimension	Basic	+0	+0	0
Radius FOS	Radius	+45.95	+46.05	0.1
Subtotal		+6.15	+6.75	0.6
Answer		+6.1500	+6.7500

See Which Plan is Right for you:

Pro

For single users looking to maximize their productivity.

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Enterprise

For teams that want to perfect their drawing review process.

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