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City of Glass

Cassandra Clare

Cover of City of Glass

City of Glass

Age Rating, Reading Level & Content Guide

The Mortal Instruments Book Three

by Cassandra Clare

Reading Level 8 12ME Ages 9-12 Balanced Read

The text is written at a 8th grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content has moderate intensity with some emotionally heavy themes.

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About This Book

There’s a secret world where Shadowhunters battle demons in the shadows, and this time, the stakes are higher than ever. Friendships will be tested, and love might just break all the rules—but that’s only the beginning.

Quick Assessment

This is the third installment in a popular fantasy series featuring a hidden world of demon hunters, vampires, and werewolves. Suitable for middle-grade readers, it explores themes of loyalty, war, and forbidden love with some complex emotional and social dynamics. Parents should note the presence of supernatural violence and romantic tension.

Why we rated City of Glass 12ME

City of Glass is written at a Level 8 reading level across 508 pages. Strong independent readers around grade 9.0 can typically handle this book on their own; with parent or teacher support, City of Glass works for readers up to grade 10.0.

We rate City of Glass as 12ME ("Moderate — Emotional") because the content sits in the "Moderate" range — moderate conflict that may involve loss, scary scenes, or interpersonal stakes. The strongest signals come from emotional weight, physical peril, social complexity, thematic difficulty — these are the dimensions parents should evaluate against their reader's tolerance.

No specific content flags were raised by community reviewers, which is consistent with the moderate intensity score.

Thematically, City of Glass explores magic, vampires, friendship, romance, and adventure — these threads give the book room to mean different things to different readers.

Good fit for

  • Children in the Ages 9-12 range — the maturity and attention span match the story's pacing.
  • Patient readers who enjoy slower, character-driven stories.
  • Kids drawn to stories about magic, vampires, friendship.

Maybe not for

  • ! Readers who get easily upset by emotional or moderately dark scenes — the conflict here is real, not just background flavor.
  • ! Reluctant readers who need a fast hook — the pacing here rewards patience.

For Parents

Content Intensity

12ME — Moderate — Emotional
Emotional
Moderate
Physical
Moderate
Social
Moderate
Thematic
Moderate

Real stakes and emotional weight. May include sustained danger, loss, or bullying.

Data confidence: standard

Was our "Moderate" content intensity rating accurate for this book?

Reading Insights

Hook Factor

2/10

A steady, thoughtful read that rewards patient readers.

Discussion Potential

2/10

A lighter read — great for independent enjoyment.

Book DNA

Multi-dimensional content fingerprint

Vocabulary Level
7
Emotional Weight
6
Theme Richness
6
World Scope
7
Data Confidence
7

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Details

Book Length

508 pages
ISBN
9781406354881
Pages
508
Publisher
Walker Books (UK)
Published
2013
Type
Fiction

Genres

Subjects

MagicVampiresClary FrayDemonologySupernaturalNew YorkQuestsFamily Secrets

Places

New York (State)New York (N.Y.)New York