How Long Is Undertale – Main Story, Endings, and Completionist Time

Toby Fox’s Undertale is one of the most iconic indie games of the last decade — a deceptively simple RPG that challenges genre conventions and player expectations. While it’s not a lengthy game by modern standards, its branching story paths and multiple endings offer vastly different playthrough experiences.

Whether you’re planning to play Undertale for the first time or looking to explore all its endings, this guide will break down how much time you can expect to spend on each route and what factors might affect your playthrough length.

Overview: What Is Undertale?

Undertale is a 2D role-playing game released in 2015, developed almost entirely by a single creator, Toby Fox. The game follows a human child who falls into the Underground, a mysterious realm filled with monsters. The player must navigate a series of puzzles, battles, and story choices that shape the outcome of the game.

The unique aspect of Undertale lies in its non-traditional combat system, which allows players to either fight enemies or resolve encounters peacefully. This core mechanic underpins the game’s three main routes — Neutral, Pacifist, and Genocide — each offering distinct narrative outcomes and gameplay experiences.

How Long Does It Take to Beat Undertale?

Your total playtime depends heavily on the route you choose and whether you’re playing blind or using a guide. Let’s break it down by route:

1. Neutral Route – 5 to 6 Hours

The Neutral Route is what most first-time players experience. It’s the default path when you complete the game without meeting the requirements for either the Pacifist or Genocide ending.

• Playtime Estimate: 5 to 6 hours for most players
• Key Features: Combination of fighting and sparing enemies, multiple ending variations depending on player choices
• Factors Influencing Time:
  • Whether you explore optional dialogue and hidden rooms
  • The number of enemy encounters you fight vs. spare
  • Puzzle-solving speed

There are more than a dozen different Neutral endings, based on specific characters’ fates, but the route structure is essentially the same. If you’re reading little and moving quickly, it’s possible to finish even sooner, but most players take around 5 to 6 hours.

2. True Pacifist Route – 7 to 9 Hours (Including Neutral First)

To unlock the True Pacifist Ending, you must first complete a Neutral playthrough and then reload your save file to complete specific conditions. This includes befriending three main characters — Papyrus, Undyne, and Alphys — and finishing a bonus area called the True Lab.

• Playtime Estimate: 7 to 9 hours total
  • Around 5–6 hours for the initial Neutral run
  • Plus 2–3 hours for the additional Pacifist content
• Key Features: You must avoid killing any enemies, including bosses
• Story Impact: You get the “true” ending of the game, with deeper lore and full character development

If you’re playing with a guide and rushing through dialogue, it can be done faster, but to fully experience the route and character arcs, 8 hours is a more realistic estimate for most players.

3. Genocide Route – 6 to 8 Hours

The Genocide Route — also known as the No Mercy Route — is the darkest and most difficult. It requires players to intentionally kill every monster in each area, which includes repeatedly grinding random encounters until you “clear” a zone. It offers unique boss fights and an entirely different narrative tone.

• Playtime Estimate: 6 to 8 hours
• Key Challenges:
  • Grind-heavy early areas (especially in Snowdin)
  • Mechanically difficult boss fights, including the infamous Sans fight
• Unique Content: Genocide-exclusive dialogue, music, and scenes

Because of the repetition required to complete this route, it may feel longer than the Pacifist run despite having less character interaction and fewer cutscenes.

If you’re attempting Sans for the first time, you can also expect several retries — possibly stretching the total time well beyond 8 hours depending on your skill level.

4. Completionist Route – 15 to 20 Hours

For those who want to experience everything Undertale has to offer, including all major routes, side content, hidden rooms, secrets, and alternate dialogue, a full playthrough will take more time.

• Playtime Estimate: 15 to 20 hours
• Includes:
  • A Neutral playthrough
  • A Pacifist replay and full route
  • A Genocide playthrough
  • Exploring Easter eggs (e.g., Gaster events, hidden NPCs)
  • Attempting rare RNG events (like the Mystery Man or Clam Girl)

This kind of deep-dive playstyle is for players who want to understand the lore and see how minor changes affect outcomes. While Undertale is compact in scope, its attention to detail rewards replaying and experimentation.

What Affects Playtime?

1. Reading Speed

The game contains a significant amount of text, humor, and branching dialogue. Players who rush through conversations will naturally finish faster, but they may miss important world-building.

2. Combat Choices

Choosing to spare enemies often requires more time and attention than simply attacking. Some fights require figuring out a character’s specific sparing mechanics, which adds time.

3. Puzzle Solving

While most puzzles are fairly simple, first-time players might spend extra time on sections like the Hotland conveyor belts or Snowdin’s tile puzzle.

4. Boss Fight Difficulty

The Genocide route in particular contains one of the most challenging boss fights in modern RPG history. The Sans battle has a notoriously high failure rate for newcomers.

Is Undertale a Short Game?

In terms of raw hours, Undertale is short compared to modern open-world RPGs or even mid-length JRPGs. However, its narrative depth, replayability, and moral consequences create a sense of scope far beyond its modest runtime.

Many players return to Undertale for second and third playthroughs to experiment with different choices. Unlike some games that simply change the ending scene, Undertale adjusts the entire experience — with new dialogue, mechanics, music, and events based on your behavior.

Summary Table: Undertale Playtime by Route

Route	Estimated Time	Key Notes
Neutral	5–6 hours	Most first-time players follow this route
True Pacifist	7–9 hours	Requires Neutral run first, includes True Lab
Genocide	6–8 hours	Grind-heavy, difficult boss fights, unique story arc
Completionist	15–20 hours	All routes + secrets, Easter eggs, alternate dialogues

Undertale may be a compact RPG in terms of length, but its design encourages players to think differently, try again, and explore its world from multiple angles. Whether you’re just in for one route or aiming to complete every possible ending, expect to spend between 5 and 20 hours depending on how deep you go.

Each route offers something new — and in true Undertale fashion, your choices don’t just matter… they shape the entire journey.