What reading level is Proof of forever?

Proof of forever by Lexa Hillyer is at a Level 5-6 reading level (Lexile 870L). Recommended for Middle Grades readers (Ages 9-12).

What age is Proof of forever appropriate for?

Proof of forever is recommended for Ages 9-12. HootRating: 10LE (Light — Emotional).

What genre is Proof of forever?

Proof of forever is fiction — Young Adult Fiction.

Does Proof of forever have any content warnings?

Proof of forever has a HootRating of 10LE (Light — Emotional). No specific content flags noted. On HootRated, every book is rated across four dimensions — emotional, physical, social, and thematic — to help parents make informed choices.

How many pages is Proof of forever?

Proof of forever by Lexa Hillyer is 339 pages.

Reviewed by HootRated editorial · Last updated September 7, 2026

Proof of forever

Lexa Hillyer

Proof of forever

Age Rating, Reading Level & Content Guide

by Lexa Hillyer

Reading Level 5-6 10LE Ages 9-12 Balanced Read

The text is written at a 5th grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content is mild with minimal sensitive material.

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About This Book

Four friends thought their perfect summer was gone forever—until a magical photo-booth flash sends them back in time! What if you could relive your best memories and fix the secrets that broke your friendships? But changing the past might change everything, and not always for the better.

Themes

Friendship Coming of AgeTime TravelAdventure Family

Quick Assessment

Proof of Forever is a lyrical middle-grade novel about friendship, time travel, and the challenges of growing up. Targeted at ages 9-12, it explores themes of reunion and secrets with emotional depth suitable for this age group. Parents should note the story touches on friendship strain and the complexities of revisiting the past.

Why we rated Proof of forever 10LE

Proof of forever is written at a Level 5-6 reading level with a Lexile measure of 870L across 339 pages. Strong independent readers around grade 6.5 can typically handle this book on their own; with parent or teacher support, Proof of forever works for readers up to grade 7.5.

We rate Proof of forever as 10LE ("Light — Emotional") 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, Proof of forever explores friendship, coming of age, time travel, adventure, and family — 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 friendship, coming of age, time travel.