Sassbook AI vs Undetectable AI

See how their public offers line up before you choose your own position. Prices stay in the currency, billing schedule, and charged unit each vendor publishes.

Sassbook AI

See full pricing history

USD · US · source: sassbook.com

Plan	Pricing	Charged by	Offer type
Free — Free	Free $0 /month	Seat · per user/seat	Standalone · Free
Standard — Monthly Highlighted	USD 15 monthly · USD 32.5 / month with annual commitment $15 /month or $32.5 /month, billed yearly	Seat · per user/seat	Standalone · Fixed
Premium — Monthly	USD 25 monthly · USD 49.16 / month with annual commitment $25 /month or $49.16 /month, billed yearly	Seat · per user/seat	Standalone · Fixed

Undetectable AI

See full pricing history

USD · US · source: undetectable.ai

Plan	Pricing	Charged by	Offer type
10K words/month — default	USD 9.99 monthly · USD 5 / month with annual commitment $5.00 /mo Charged annually $60.00	Usage · 10K words/month	Standalone · Fixed
20K words/month — default	USD 19 monthly · USD 9.5 / month with annual commitment $9.50 /mo Charged annually $114.00	Usage · 20K words/month	Standalone · Fixed
35K words/month — default	USD 31 monthly · USD 15.75 / month with annual commitment $15.75 /mo Charged annually $189.00	Usage · 35K words/month	Standalone · Fixed
50K words/month — default	USD 42.5 monthly · USD 21.25 / month with annual commitment $21.25 /mo	Usage · 50K words/month	Standalone · Fixed

What each plan includes

Feature names follow each vendor’s own pricing page, so verify the wording before treating them as exact equivalents.

Sassbook AI

Free — Free

Highlights API Credits: $0 /month

Included
Highlights Words per generation (AI Writer + AI Story Writer): 50

Included
Highlights Candidates per generation (AI Writer + AI Story Writer): 2

Included
Highlights Generations per day (AI Writer + AI Story Writer): 20

Included
Highlights Pages per summarization (AI Summarizer): 2.5

Included
Highlights Summaries per day (AI Summarizer): 15

Included
Highlights Pages per paraphrase generation (AI Paraphraser): 0.3

Included
Highlights Paraphrase generations per day (AI Paraphraser): 10

Included
Highlights Pages per headline generation (AI Headline Generator): 0.5

Included
Highlights Headline generations per day (AI Headline Generator): 10

Included
Highlights Priority processing: Included

Standard — Monthly

Highlights API Credits: $15 /month

Included
Highlights Words per generation (AI Writer + AI Story Writer): 70

Included
Highlights Candidates per generation (AI Writer + AI Story Writer): 4

Included
Highlights Generations per day (AI Writer + AI Story Writer): Unlimited

Included
Highlights Pages per summarization (AI Summarizer): 10

Included
Highlights Summaries per day (AI Summarizer): Unlimited

Included
Highlights Pages per paraphrase generation (AI Paraphraser): 10

Included
Highlights Paraphrase generations per day (AI Paraphraser): Unlimited

Included
Highlights Pages per headline generation (AI Headline Generator): 1.6

Included
Highlights Candidates per generation (AI Headline Generator): 5

Included
Highlights Headline generations per day (AI Headline Generator): Unlimited

Included
Highlights Priority processing: Included

Premium — Monthly

Highlights API Credits: $25 /month

Included
Highlights Words per generation (AI Writer + AI Story Writer): 100

Included
Highlights Candidates per generation (AI Writer + AI Story Writer): 6

Included
Highlights Generations per day (AI Writer + AI Story Writer): Unlimited

Included
Highlights Pages per summarization (AI Summarizer): 20

Included
Highlights Summaries per day (AI Summarizer): Unlimited

Included
Highlights Pages per paraphrase generation (AI Paraphraser): 20

Included
Highlights Paraphrase generations per day (AI Paraphraser): Unlimited

Included
Highlights Pages per headline generation (AI Headline Generator): 1.6

Included
Highlights Candidates per generation (AI Headline Generator): 10

Included
Highlights Headline generations per day (AI Headline Generator): Unlimited

Included
Highlights Priority processing: Included

Undetectable AI

10K words/month — default

Highlights Passes AI detectors: Included
Highlights High quality, legible content: Included
Highlights Watermark and future proof: Included
Highlights Writing level matching: Included
Highlights API compatible: Included
Highlights Unlimited Human Auto Typer: Included
Highlights Unlimited AI Detecting: Included

20K words/month — default

Highlights Passes AI detectors: Included
Highlights High quality, legible content: Included
Highlights Watermark and future proof: Included
Highlights Writing level matching: Included
Highlights API compatible: Included
Highlights Unlimited Human Auto Typer: Included
Highlights Unlimited AI Detecting: Included

35K words/month — default

Highlights Passes AI detectors: Included
Highlights High quality, legible content: Included
Highlights Watermark and future proof: Included
Highlights Writing level matching: Included
Highlights API compatible: Included
Highlights Unlimited Human Auto Typer: Included
Highlights Unlimited AI Detecting: Included

50K words/month — default

Highlights Passes AI detectors: Included
Highlights High quality, legible content: Included
Highlights Watermark and future proof: Included
Highlights Writing level matching: Included
Highlights API compatible: Included
Highlights Unlimited Human Auto Typer: Included
Highlights Unlimited AI Detecting: Included

How their prices changed

Each dated row shows the public prices observed when that vendor’s pricing page changed.

Sassbook AI

August 27, 2026 Source
- Free — Free: Free
- Standard — Monthly: USD 15 monthly · USD 32.5 / month with annual commitment
- Premium — Monthly: USD 25 monthly · USD 49.16 / month with annual commitment

Undetectable AI

August 27, 2026 Source
- 10K words/month — default: USD 9.99 monthly · USD 5 / month with annual commitment
- 20K words/month — default: USD 19 monthly · USD 9.5 / month with annual commitment
- 35K words/month — default: USD 31 monthly · USD 15.75 / month with annual commitment
- 50K words/month — default: USD 42.5 monthly · USD 21.25 / month with annual commitment