City of Glass

Name: City of Glass
Author: Cassandra Clare
ISBN: 9781416914303

Age Rating, Reading Level & Content Guide

The Mortal Instruments Book 3

by Cassandra Clare

Reading Level 4-5 LP · Mild · Physical Ages 13+ Balanced Read

The text is written at a 4th grade reading level, the subject matter is intended for teens (ages 13+), and the content is mild with minimal sensitive material. Its HootRating code, LP, means mild content, mostly physical.

Find on Amazon Listen on Audible Find on Bookshop.org

We may earn a commission from these links. Bookshop.org supports independent bookstores with every purchase.

About This Book

Here's a secret: Simon is no ordinary vampire—he shines in the daylight and holds the key to peace between two very different worlds. But when mysterious murders stir up trouble, Simon must step into the shadows to solve the mystery. And that's only the beginning.

Themes

SupernaturalFictionMagicVampiresDemonologyMystery Adventure

Quick Assessment

When mysterious murders threaten the fragile peace between Shadowhunters and Downworlders, Clary must enter the City of Glass to save her mother while Simon is imprisoned and Valentine plots to destroy all Shadowhunters. Parents should know about fantasy violence, an amputation, a character death, a kidnapping, ghostly and bug-filled scenes, animal abuse, and hateful speech aimed at Downworlders. The story also includes a romance that later reveals a family secret, and a minor is sexualized in a way that is worth discussing with younger readers.

Why we rated City of Glass LP (Mild)

City of Glass is written at a Level 4-5 reading level across 541 pages. Upper Grades (Ages 13+) is the typical interest range for this book — readers in that age band have the maturity and attention span suited to the story, separate from whether they can decode the words.

We rate City of Glass as LP (Mild, mostly physical) because the content sits in the "Mild" range — mild conflict — the kind a child encounters in normal play and sibling life. Across our four dimensions (emotional, physical, social, thematic) the book reads as evenly mild; no single dimension stands out as a concern.

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

Thematically, City of Glass explores supernatural, fiction, magic, vampires, and demonology — these threads give the book room to mean different things to different readers.

Good fit for

✓ Children in the Ages 13+ range — the maturity and attention span match the story's pacing.
✓ Kids drawn to stories about supernatural, fiction, magic.

Maybe not for

! Readers looking for something heavier — this is a gentle, low-stakes story by design.

For Parents

Content Intensity

LP · Mild · Physical

Emotional

Mild

Physical

Mild ←

Social

Gentle

Thematic

Mild

Reading the HootRating code: the first letter is the content intensity (C = Gentle · L = Mild · M = Moderate · I = Intense · V = Very Intense); the second, when there is one, is the kind of content that drives it (E = Emotional · P = Physical · S = Social · T = Thematic). Reading level and age range are rated separately. How we rate

Light conflict or tension. Mild peril resolved quickly.

Data confidence: high

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