Which S3 class is cheapest for storage?

Glacier Deep Archive has the lowest per-GB storage price, designed for data accessed once or twice a year with retrieval times of up to 12 hours (standard) or 48 hours (bulk). It carries a 180-day minimum storage duration, so early deletes are still billed for the full period.

What is the difference between Standard-IA and One Zone-IA?

Both are for infrequently accessed data with a retrieval fee, but Standard-IA stores data across three or more Availability Zones while One Zone-IA keeps a single copy in one zone. One Zone-IA is about 20% cheaper but loses data if that zone is destroyed, so use it only for re-creatable data.

When should I use Intelligent-Tiering?

Use Intelligent-Tiering when access patterns are unknown or changing. It automatically moves objects between frequent, infrequent and optional archive tiers based on usage, with no retrieval fees and a small per-object monitoring charge. It avoids retrieval penalties from guessing the wrong class.

What does minimum storage duration mean?

IA and archive classes bill for a minimum number of days even if you delete the object sooner: 30 days for Standard-IA and One Zone-IA, 90 days for Glacier Flexible Retrieval and Glacier Instant Retrieval, and 180 days for Glacier Deep Archive. Frequent churn in these classes can cost more than Standard.

Which class gives millisecond retrieval for archives?

Glacier Instant Retrieval offers archive-level storage pricing with millisecond access, suited to long-lived data accessed once a quarter (such as medical images or media archives). The cheaper Glacier Flexible Retrieval and Deep Archive trade that for minutes-to-hours retrieval times.

What is the AWS S3 Storage Classes Reference?

Reference for Amazon S3 storage classes from Standard to Glacier Deep Archive with retrieval latency, durability, availability zones, minimum storage duration and cost tier. It runs free in your browser on Gera Tools, with nothing uploaded.

AWS S3 Storage Classes Reference

Name: AWS S3 Storage Classes Reference
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Amazon S3 storage classes

S3 storage classes let you trade retrieval speed for storage price. Picking the right one cuts the bill dramatically for cold data — but each colder class adds retrieval fees and minimum-duration charges. This reference covers every general storage class with its durability, availability-zone footprint, retrieval latency, minimum duration and relative cost tier.

How it works

All S3 classes share the same eleven-nines (99.999999999%) durability for multi-AZ classes; they differ on availability, retrieval and price. The cost model has three levers:

total cost = storage $/GB-month + request/retrieval fees + min-duration charge

Hot (Standard, Express One Zone): no retrieval fee, highest storage price, used for active data.
Infrequent (Standard-IA, One Zone-IA): lower storage price + a per-GB retrieval fee + 30-day minimum.
Archive (Glacier Instant, Glacier Flexible, Deep Archive): lowest storage price, retrieval from milliseconds to 48 hours, 90–180-day minimum.
Auto (Intelligent-Tiering): moves objects between tiers automatically, no retrieval fees, small monitoring charge per object.

Storage class comparison table

Class	AZ footprint	Retrieval latency	Min storage duration	Best for
Standard	≥3 AZs	Milliseconds	None	Active, frequently read data
Intelligent-Tiering	≥3 AZs	Milliseconds (frequent tier)	None	Unknown or changing access patterns
Standard-IA	≥3 AZs	Milliseconds (+ retrieval fee)	30 days	Backups accessed monthly
One Zone-IA	1 AZ	Milliseconds (+ retrieval fee)	30 days	Re-creatable data, secondary copies
Glacier Instant Retrieval	≥3 AZs	Milliseconds (+ retrieval fee)	90 days	Long-lived data accessed quarterly
Glacier Flexible Retrieval	≥3 AZs	1–12 hours (tiered)	90 days	DR archives, long-term backups
Glacier Deep Archive	≥3 AZs	Up to 48 hours	180 days	Regulatory retention, rarely accessed
Express One Zone	1 AZ	Single-digit milliseconds	1 hour	High-performance, latency-sensitive apps

Choosing the right class

If you read data daily or more: Standard is the baseline. The slightly higher storage price is offset by no retrieval fees, and you avoid any risk of minimum-duration overage.

If your access pattern is unpredictable: Intelligent-Tiering watches each object for 30 consecutive days of no access and moves it to the infrequent tier automatically, with no retrieval fee. It charges a small per-object monitoring fee, which makes it cost-ineffective for tiny objects (a few KB), but it is ideal for large media libraries or datasets with seasonal spikes.

If you know data will be accessed once a month or less: Standard-IA gives a meaningful storage price reduction. The catch is the 30-day minimum: deleting or transitioning an object before 30 days still charges for 30 days. This class is cost-effective only for data that genuinely sits untouched for months.

For archive data you might need in an emergency: Glacier Instant Retrieval provides archive-level storage pricing but millisecond access — closer to Standard-IA in retrieval behaviour but with a 90-day minimum. Ideal for medical images, media masters, or compliance records that are almost never opened but occasionally needed urgently.

For long-term backups measured in years: Glacier Flexible Retrieval or Deep Archive. Use Expedited retrieval on Flexible if you might need something within minutes; plan for 12-hour Standard retrieval for the normal case. Deep Archive’s bulk retrieval can take up to 48 hours — it is appropriate only for data where retrieval is a planned, rare event.

Tips and notes

Lifecycle rules transition objects between classes by age — never move tiny or short-lived objects to IA/archive; the minimum-duration charge eats the saving.
One Zone classes are not zone-redundant: use only for data you can regenerate.
Glacier Flexible Retrieval offers Expedited (1–5 min), Standard (3–5 h) and Bulk (5–12 h) retrieval options at different prices.
Deep Archive is the floor on storage price but the slowest to read — plan for up to 48-hour bulk retrieval.
Intelligent-Tiering has an optional archive activation for objects inactive for 90 or 180 days, extending savings further at the cost of longer retrieval.