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INT. vs EXT. — Scene Headings Explained

March 15, 2026 · by David Kaufman · 8 min read

One of the first things screenwriters learn is that every scene begins with a scene heading—sometimes called a slug line. These tiny lines pack enormous information into just a few words, and they're essential to professional screenplay formatting. Understanding the difference between INT. and EXT. (and when to use each) is a fundamental skill that separates polished scripts from amateur work.

In this guide, we'll break down exactly what INT. and EXT. mean, why they matter, and how to use them correctly in your screenplay.

What Is a Scene Heading (Slug Line)?

A scene heading is the line that appears before every scene in your screenplay. It tells the reader—and eventually the production team—where and when the scene takes place. Think of it as a mini-map that orients everyone to the location and time of day.

Scene headings follow this standard format:

[INT./EXT.] [LOCATION] — [TIME OF DAY]

For example:

INT. COFFEE SHOP — MORNING
EXT. NEW YORK STREET — NIGHT
INT./EXT. MOVING CAR — CONTINUOUS

Every word in a scene heading should be in capital letters, and it should appear in a Courier 12-point font. When you're writing in a professional screenwriting application like MyWriters.life, the screenplay formatter will handle capitalization and font automatically, so you can focus on getting the content right.

INT. — Interior Locations

INT. stands for interior. Use this when your scene takes place inside a building, vehicle, or enclosed space where the ceiling or walls protect the characters from the elements.

Common INT. locations include:

Bedrooms, kitchens, living rooms (homes)
Offices, boardrooms, cubicles
Restaurants, bars, coffee shops
Cars, buses, trains, airplanes
Hospitals, police stations, courtrooms
Stores, warehouses, factories
Movie theaters, gyms, hotels

Here are some examples of properly formatted INT. scene headings:

INT. BEDROOM — NIGHT
INT. DINER — DAY
INT. ELEVATOR — CONTINUOUS
INT. DETECTIVE'S OFFICE — MORNING

The key question: Is the scene protected from weather and natural light? If yes, it's INT.

EXT. — Exterior Locations

EXT. stands for exterior. Use this when your scene takes place outdoors, exposed to the sky, sun, rain, wind, and weather. If there's no ceiling above the action (or only a partial covering like an awning), it's EXT.

Common EXT. locations include:

Streets, parks, beaches
Rooftops, balconies, fire escapes
Forests, mountains, deserts
Parking lots, sidewalks, plazas
Sports fields, playgrounds, gardens
Highways, rural roads, bridges
Piers, docks, lakes

Here are some examples of properly formatted EXT. scene headings:

EXT. CENTRAL PARK — DAY
EXT. BROOKLYN ROOFTOP — NIGHT
EXT. MOUNTAIN TRAIL — MORNING
EXT. PARKING LOT — DUSK

The key question: Is the scene exposed to the elements? If yes, it's EXT.

The Gray Area: INT./EXT. Locations

Sometimes a scene takes place in a space that's neither fully interior nor fully exterior. Examples include:

A covered patio or gazebo
An open-air market with a partial roof
A greenhouse
A train station platform (often under a partial structure)
A parking garage
An airport terminal (partially open to outside)

In these cases, use INT./EXT. to indicate that the scene has elements of both. If the scene involves characters moving between inside and outside (like walking from a house through the front door to the porch), you can also use INT./EXT.

Example:

INT./EXT. TRAIN STATION PLATFORM — MORNING
INT./EXT. HOUSE PORCH — DUSK

Don't overuse INT./EXT. If the scene is clearly mostly inside or mostly outside, stick with INT. or EXT. alone. Save INT./EXT. for genuinely ambiguous spaces.

Time of Day: The Third Component

The time of day in a scene heading communicates mood, lighting, and production logistics. The most common options are:

DAY — Daytime, sunlight visible
NIGHT — Nighttime, dark or artificial lighting
MORNING — Early daylight (sunrise or early hours)
AFTERNOON — Midday or early evening
DUSK — Twilight, golden hour or early dark
DAWN — Very early morning, sunrise
CONTINUOUS — Scene continues immediately from the previous scene without time passing
LATER — Same day, but hours have passed

Examples:

INT. KITCHEN — MORNING
EXT. FOREST — NIGHT
INT. CAR — CONTINUOUS
EXT. BEACH — DUSK

For most scripts, stick with DAY and NIGHT. These are the clearest for both readers and production teams. Use more specific times only when lighting or mood is crucial to the scene.

Capitalization and Format Rules

Scene headings have strict formatting requirements. Here's what you need to know:

Always capitalize INT., EXT., and INT./EXT.
Always capitalize all location names and time of day
Use periods after INT. and EXT. (INT., EXT., INT./EXT.)
Use a dash (—) to separate location from time of day
Use proper formatting: No more, no less. Don't add unnecessary details.

Incorrect formatting:

int. coffee shop — morning (not capitalized)
INTERIOR COFFEE SHOP — MORNING (too verbose, use INT.)
INT COFFEE SHOP - MORNING (missing period and uses hyphen instead of dash)
INT. COFFEE SHOP BOOTH — MORNING (overly specific)

Correct formatting:

INT. COFFEE SHOP — MORNING
INT. COFFEE SHOP — DAY
INT./EXT. COFFEE SHOP PATIO — AFTERNOON

Common Mistakes to Avoid

1. Being Too Specific with Locations

Screenplays should suggest locations, not dictate them. Avoid overly detailed scene headings:

Wrong: INT. SARAH'S BEDROOM WITH BLUE WALLS AND A POSTER OF MARILYN MONROE — NIGHT
Right: INT. SARAH'S BEDROOM — NIGHT

The action lines below the scene heading will show the blue walls and poster. The scene heading just needs to orient the reader to location and time.

2. Inconsistent Location Names

If a location appears multiple times in your script, use the same name every time. This helps with script continuity and production budgeting.

Don't alternate between: INT. KITCHEN — DAY and INT. FAMILY KITCHEN — DAY
Pick one: INT. KITCHEN — DAY (every time)

3. Confusing Time Indicators

Don't invent time indicators. Stick to standard terminology:

Wrong: INT. OFFICE — LATE AFTERNOON (use AFTERNOON or DUSK)
Wrong: INT. BEDROOM — EARLY MORNING (use MORNING or DAWN)
Right: INT. OFFICE — AFTERNOON or EXT. GARDEN — DAWN

4. Mixing INT./EXT. When Unnecessary

Use INT./EXT. only when the location truly has both interior and exterior elements. A car in a parking lot is still INT. (the car's interior is enclosed):

Wrong: INT./EXT. CAR IN PARKING LOT — DAY
Right: INT. CAR — DAY (the location is the car's interior)

Scene Headings in Different Screenplay Types

The INT./EXT. rule applies across all screenplay formats. Whether you're writing a feature film, TV pilot, short film, or web series, scene headings follow the same rules. When you're starting a new project, using a professional feature film screenplay template or TV pilot template will ensure your scene headings are formatted correctly from the start.

For a quick understanding of how scene headings fit into overall screenplay structure, read our industry-standard screenplay formatting rules guide, which covers all the technical requirements screenwriters need to master.

Pro Tips for Writing Scene Headings

Use Scene Headings to Control Pacing

Frequent location changes suggest a faster, more energetic pace. Fewer location changes create intimacy and intensity. A dialogue-heavy scene in one room feels different than a montage that jumps between multiple locations. Your scene headings shape the reader's perception of rhythm.

Think Like a Production Designer

Every INT. and EXT. has production implications. INT. scenes require lighting rigs and control of natural light. EXT. scenes are weather-dependent and harder to control. Knowing this helps you write more producible scripts. When you use INT./EXT. locations sparingly and logically, producers take your script more seriously.

Use Location Names Cinematically

Instead of generic names, use location names that hint at character or mood:

INT. SEEDY MOTEL ROOM — NIGHT (tells us something)
INT. LUXURY PENTHOUSE — DAY (paints a picture)
EXT. ABANDONED FACTORY — DUSK (suggests danger)

These names should still be simple—just one or two words—but they're more evocative than "INT. ROOM — NIGHT."

If you're working on a longer project, use a scene estimator to plan how many scenes you'll need and how locations will repeat throughout your script. This helps you manage location variety and production feasibility.

Formatting Tools Make This Easier

While understanding INT. and EXT. is essential, getting the formatting perfect can be tedious. If you're writing by hand or in a word processor, it's easy to slip up on capitalization, dash styles, or spacing. That's where a dedicated screenwriting tool helps. MyWriters.life's screenplay formatter automatically handles scene heading capitalization, font, and spacing—so you can type the content and let the software handle the formatting.

This is especially valuable when you're revising. You can focus on improving scenes and pacing without worrying about whether you used the correct dash or capitalized the location correctly.

Conclusion

INT. and EXT. are the foundation of professional screenplay formatting. INT. signals interior locations protected from the elements; EXT. signals outdoor, exposed spaces. Most scenes are clearly one or the other, though INT./EXT. works for genuinely ambiguous spaces. Combined with a clear location name and time of day, your scene heading tells readers everything they need to know about where and when the action happens.

Mastering scene headings is a small detail with big impact. Producers, directors, and fellow screenwriters instantly recognize a professionally formatted script. Getting this right—along with the rest of your formatting—shows you understand the craft and respect industry standards.

As you write your next screenplay, pay attention to your scene headings. Make them clear, consistent, and cinematically useful. Your script will look more professional, read more smoothly, and stand out to anyone who opens it.

scene headings INT EXT slug line formatting