AutoCAD F3 Shortcut :Toggle Object Snap Mode

If you work in AutoCAD and need precise placement or object-to-object snapping, the F3 key is one of the fastest toggles you can use. This guide explains exactly what the F3 (Object snap) shortcut does, how to use it step‑by‑step, alternatives, common problems and fixes, and practical tips to speed up your drafting.

What is the F3 shortcut?

F3 is the AutoCAD shortcut that toggles the running Object Snap (OSNAP) system on and off. When Object Snap is enabled, AutoCAD snaps cursor input to specific geometric points (endpoints, midpoints, intersections, centers, etc.), improving drawing accuracy and enabling exact connections between objects.

Key related shortcuts and terms:

F3 — Toggle Object Snap (running osnap).
F11 — Toggle object snap tracking (tracking lines/guides).
F9 — Toggle Grid Snap (different from osnap).
drafting settings / Object Snap — dialog to choose which snap modes are active.
OSMODE — system variable that stores the active osnap modes (bit-coded).

Why and when to use F3

Use F3 when you want AutoCAD to automatically lock the cursor to precise geometric points while you draw or edit.
Press F3 to quickly enable/disable Object Snap when switching between rough placement and precise alignment.
Combine with Object Snap Tracking (F11) for guided alignment using temporary tracking lines.

How to use F3 (step-by-step)

1) Quick toggle

Press F3 once to turn ON running Object Snap. Press F3 again to turn it OFF.
Verify the status: check the Object Snap icon in the status bar — it indicates ON/OFF.

2) Confirm which snap types are active

Open the Drafting Settings dialog: type DSETTINGS or right-click the Object Snap status bar icon → choose Settings… → go to the Object Snap tab.
Check the snap modes you want, for example Endpoint, Midpoint, Intersection, Center, Perpendicular, Tangent, Nearest, etc.
Click OK. Now pressing F3 toggles all selected osnap modes together.

3) Use drawing commands with osnap

Start any command that requests a point (e.g., LINE, MOVE, COPY, TRIM).
Hover near a snap point — AutoCAD will highlight the snap marker (square, triangle, etc.). Click to accept that precise point.
Example: Draw a new line from one object endpoint to another; with F3 ON and Endpoint enabled, the cursor will lock to those endpoints.

4) Temporary overrides while in a command

Use Shift + Right‑Click (or right‑click and choose the override) to show the Object SNAP shortcut menu and force a specific snap for the next pick (e.g., Endpoint, Midpoint, Intersection).
Type an osnap name during a command (e.g., type END or MID) on the command line if you prefer keyboard entry.

5) Use system variable to set modes directly (advanced)

Type OSMODE at the command line and enter a numeric value representing a combination of snap modes (bit-coded). Example: to enable Endpoint + Midpoint + Intersection, enter 35 (1 + 2 + 32). Use Drafting Settings for an easier method.

Alternatives to pressing F3

Click the Object Snap button on the status bar to toggle ON/OFF.
Open Drafting Settings → Object Snap to enable or disable individual snap types without toggling the global on/off.
Use Shift + Right‑Click while in a command to choose one-off osnap overrides.
Use the OSNAP command (older versions) or OSMODE (to change modes numerically).
Use Object Snap Tracking (F11) for guidance and preview lines without altering object geometry.

Common problems and how to fix them

Problem: F3 doesn’t seem to work (pressing F3 has no effect)

Check Fn/Function Lock: Many laptops require Fn + F3 or toggling the Fn Lock key to use F-keys. Try Fn + F3.
Check keyboard shortcuts customization: In rare cases, F3 may be remapped in the CUI editor.
Verify focus: Make sure AutoCAD window is active and no modal dialog is open.
Check status bar: The Object Snap icon may be hidden — right‑click the status bar and enable Object Snap to show it.
Function keys blocked by OS utilities: Some keyboard utilities or OS shortcuts may intercept F3 — close those utilities to test.
Using AutoCAD for Mac: Some Mac keyboards require different key combos or preferences; consult AutoCAD for Mac help.

Problem: F3 is ON but you’re not snapping to the expected points

Verify which osnap modes are selected in Drafting Settings. Enabling F3 only toggles the modes that are selected — it won’t auto-select endpoint if it’s unchecked.
Objects on different layers with different snap settings? Snaps are geometry-based; ensure you’re near the exact snap point and zoomed in if needed.
Drawing units or drawing is scaled? If objects are extremely large or tiny relative to the screen, snap markers may be hard to see — zoom closer.
Using 3D objects or UCS differences: Ensure you’re working in the correct UCS or set Apparent Intersection if needed.

Problem: Snaps appear but picks don’t happen when drawing

Make sure you click when the snap marker appears; sometimes clicking too early or late misses the snap.
Disable dynamic input temporarily (press F12) if it interferes with coordinate input (rare).

Problem: Need only a temporary snap (don’t want to toggle F3)

Use Shift + Right‑Click and select the desired osnap override for a single point.

Tips and best practices

Always enable the most commonly used snap modes (Endpoint, Midpoint, Center, Intersection, Nearest) in Drafting Settings to speed drafting.
Use F3 to toggle snapping quickly during geometry construction — turn it off for freehand placement, then on for precise connections.
Combine F3 (osnap) with F11 (object snap tracking) to create precise alignment guides without drawing construction geometry.
Use Shift + Right‑Click overrides for instant single-use snaps without changing global settings.
If you share drawings, ensure collaborators have the same OSNAP settings or document required settings to maintain consistency.
Learn a few common OSMODE numeric combinations if you manage scripts or batch setups.

FAQ

Why does F3 toggle on but I still can’t snap to endpoints?

If F3 is ON but endpoints are not used, check Drafting Settings → Object Snap to ensure Endpoint is selected. Also confirm you are close enough to the endpoint and not in a different UCS or drawing scale that hides the snap marker.

How do I enable only specific snap types without toggling everything?

Open Drafting Settings → Object Snap (or type DSETTINGS) and check only the snap modes you want. Press F3 to enable running osnap for those selected modes.

What’s the difference between Snap (F9) and Object Snap (F3)?

Snap (F9) is a grid-based constraint that locks the cursor to a uniform grid (useful for regular spacing). Object Snap (F3) snaps the cursor to specific geometric points on objects (endpoints, midpoints, intersections). They serve different purposes and can both be used together.

How can I do a single-use snap type while drawing?

While in a command, press Shift + Right‑Click to open the Object Snap shortcut menu and pick the snap you want for the next pick (e.g., Midpoint, Intersection). This does not change your global osnap settings.

Why does F3 behave differently on my laptop?

Many laptops require pressing the Fn key to use function keys as F1–F12. Try Fn + F3 or toggle the keyboard’s Fn Lock. Also, operating system utilities or keyboard drivers can remap function keys.

Can I change the F3 key mapping if I want a different shortcut?

Yes — open the CUI (Customize user interface) editor to remap keyboard shortcuts. Be cautious when changing defaults to avoid conflicts with other CAD workflows.

Does F3 work the same in AutoCAD LT or AutoCAD for Mac?

The function is available in AutoCAD LT and most AutoCAD versions, but Mac versions may have different keyboard shortcuts or require different key combinations. Consult the version-specific help if behavior differs.