Amazon Simple Storage Service FAQs

Find more answers in Amazon S3 Technical FAQs

General

Q: What is Amazon S3?

Amazon S3 is storage for the Internet. It’s a simple storage service that offers software developers a highly-scalable, reliable, and low-latency data storage infrastructure at very low costs.

Q: What can I do with Amazon S3?

Amazon S3 provides a simple web services interface that you can use to store and retrieve any amount of data, at any time, from anywhere on the web. Using this web service, developers can easily build applications that make use of Internet storage. Since Amazon S3 is highly scalable and you only pay for what you use, developers can start small and grow their application as they wish, with no compromise on performance or reliability. It is designed to be highly flexible: Store any type and amount of data that you want; read the same piece of data a million times or only for emergency disaster recovery; build a simple FTP application, or a sophisticated web application such as the Amazon.com retail web site. Amazon S3 frees developers to focus on innovation, not figuring out how to store their data.

Q: How can I get started using Amazon S3?

To sign up for Amazon S3, click the “Sign up for This Web Service” button on the Amazon S3 detail page. You must have an Amazon Web Services account to access this service; if you do not already have one, you will be prompted to create one when you begin the Amazon S3 sign-up process. After signing up, please refer to the Amazon S3 documentation and sample code in the Resource Center to begin using Amazon S3.

Q: What are the technical benefits of Amazon S3?

Amazon S3 was carefully engineered to meet the requirements for scalability, reliability, speed, low-cost, and simplicity that must be met for Amazon’s internal developers. Amazon S3 passes these same benefits onto any external developer. More information about the Amazon S3 design requirements is available on the Amazon S3 detail page.

Q: What can developers do now that they could not before?

Until now, a sophisticated and scalable data storage infrastructure like Amazon’s has been beyond the reach of small developers. Amazon S3 enables any developer to leverage Amazon’s own benefits of massive scale with no up-front investment or performance compromises. Developers are now free to innovate knowing that no matter how successful their businesses become, it will be inexpensive and simple to ensure their data is quickly accessible, always available, and secure.

Q: Can I host my static website on Amazon S3?

Yes, you can host your entire static website on Amazon S3. Customers commonly store images, video, and other content for their website on Amazon S3. You can also take advantage of root and index document support as well as custom HTML errors to host your entire website from your Amazon S3 bucket. To learn more about hosting your website on Amazon S3, please visit the Amazon S3 Developer Guide.

Q: What kind of data can I store?

You can store virtually any kind of data in any format. Please refer to the Amazon Web Services Licensing Agreement for details.

Q: How much data can I store?

The total volume of data and number of objects you can store are unlimited. Individual Amazon S3 objects can range in size from 1 byte to 5 terabytes. The largest object that can be uploaded in a single PUT is 5 gigabytes. For objects larger than 100 megabytes, customers should consider using the Multipart Upload capability.

Q: How can I delete large numbers of objects?

You can use Multi-Object Delete to delete large numbers of objects from Amazon S3. This feature allows you to send multiple object keys in a single request to speed up your deletes. Amazon does not charge you for using Multi-Object Delete.

Q: How can I configure my objects to be deleted after a specific time period?

You can use the Object Expiration feature to remove objects from your buckets after a specified number of days. You can define the expiration rules for a set of objects in your bucket through the Lifecycle Configuration policy that you apply to the bucket. Each Object Expiration rule allows you to specify a prefix and an expiration period. The prefix field identifies the objects subject to the rule. To apply the rule to an individual object, specify the key name. To apply the rule to a set of objects, specify their common prefix (e.g. “logs/”). For expiration period, provide the number of days from creation date (i.e. age) after which you want your objects removed. You may create multiple rules for different prefixes. For example, you could create a rule that removes all objects with the prefix “logs/” 30 days from creation, and a separate rule that removes all objects with the prefix “backups/” 90 days from creation.

After an Object Expiration rule is added, the rule is applied to objects that already exist in the bucket as well as new objects added to the bucket. Once objects are past their expiration date, they are identified and queued for removal. You will not be billed for storage for objects on or after their expiration date, though objects may still be accessible while they are in queue before they are removed. As with standard delete requests, Amazon S3 doesn’t charge you for removing objects using Object Expiration. For more information on using Object Expiration, please refer to the Object Expiration topic in the Amazon S3 Developer Guide.

Q: What does Amazon do with my data in Amazon S3?

Amazon will store your data and track its associated usage for billing purposes. Amazon will not otherwise access your data for any purpose outside of the Amazon S3 offering, except when required to do so by law. Please refer to the Amazon Web Services Licensing Agreement for details.

Q: Does Amazon store its own data in Amazon S3?

Yes. Developers within Amazon use Amazon S3 for a wide variety of projects. Many of these projects use Amazon S3 as their authoritative data store, and rely on it for business-critical operations.

Q: How is Amazon S3 data organized?

Amazon S3 is a simple key-based object store. When you store data, you assign a unique object key that can later be used to retrieve the data. Keys can be any string, and can be constructed to mimic hierarchical attributes.

Q: How do I interface with Amazon S3?

Amazon S3 provides simple, standards-based REST and SOAP web services interfaces that are designed to work with any Internet-development toolkit. The operations are intentionally made simple to make it easy to add new distribution protocols and functional layers.

Q: How reliable is Amazon S3?

Amazon S3 gives any developer access to the same highly scalable, reliable, fast, inexpensive data storage infrastructure that Amazon uses to run its own global network of web sites. The service was designed for 99.99% availability, and carries a service level agreement providing service credits if a customer’s availability falls below 99.9%.

Q: What data consistency model does Amazon S3 employ?

Amazon S3 buckets in the US West (Oregon), US West (Northern California), EU (Ireland), Asia Pacific (Singapore), Asia Pacific (Tokyo), and South America (Sao Paulo) Regions provide read-after-write consistency for PUTS of new objects and eventual consistency for overwrite PUTS and DELETES. Amazon S3 buckets in the US Standard Region provide eventual consistency.

Q: What happens if traffic from my application suddenly spikes?

Amazon S3 was designed from the ground up to handle traffic for any Internet application. Pay-as-you-go pricing and unlimited capacity ensures that your incremental costs don’t change and that your service is not interrupted. Amazon S3’s massive scale enables us to spread load evenly, so that no individual application is affected by traffic spikes.

Q: What is the BitTorrent™ protocol, and how do I use it with Amazon S3?

BitTorrent is an open source Internet distribution protocol. Amazon S3’s bandwidth rates are inexpensive, but BitTorrent allows developers to further save on bandwidth costs for a popular piece of data by letting users download from Amazon and other users simultaneously. Any publicly available data in Amazon S3 can be downloaded via the BitTorrent protocol, in addition to the default client/server delivery mechanism. Simply add the ?torrent parameter at the end of your GET request in the REST API.

Q: Does Amazon S3 offer a Service Level Agreement (SLA)?

Yes. The Amazon S3 SLA provides for a service credit if a customer’s monthly uptime percentage is below our service commitment in any billing cycle. More information can be found here.

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Regions

Q: Where is my data stored?

Amazon S3 offers storage in the US Standard, US West (Oregon), US West (Northern California), EU (Ireland), Asia Pacific (Singapore), Asia Pacific (Tokyo), South America (Sao Paulo), and AWS GovCloud (US) Regions. You specify a Region when you create your Amazon S3 bucket. Within that Region, your objects are redundantly stored on multiple devices across multiple facilities.

Q: How do I decide which Region to store my data in?

There are several factors to consider based on your specific application. You may want to store your data in a Region that…

• ...is near to your customers, your data centers, or your other AWS resources in order to reduce data access latencies.
• ...is remote from your other operations for geographic redundancy and disaster recovery purposes.
• ...enables you to address specific legal and regulatory requirements.
• ...allows you to reduce storage costs. You can choose a lower priced Region to save money. Please see the pricing section on the S3 detail page.

Q: I’m not in the US or Europe; can I use Amazon S3?

Anyone can use Amazon S3. You just have to decide which Region you want Amazon S3 to store your data in.

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Billing

Q: How much does Amazon S3 cost?

With Amazon S3, you pay only for what you use. There is no minimum fee. You can estimate your monthly bill using the AWS Simple Monthly Calculator.

We charge less where our costs are less. Some prices vary across Amazon S3 Regions and are based on the location of your bucket. There is no Data Transfer charge for data transferred within an Amazon S3 Region via a COPY request. Data transferred via a COPY request between Regions is charged at regular rates. There is no Data Transfer charge for data transferred between Amazon EC2 and Amazon S3 within the same Region or for data transferred between the Amazon EC2 Northern Virginia Region and the Amazon S3 US Standard Region. Data transferred between Amazon EC2 and Amazon S3 across all other Regions (i.e. between the Amazon EC2 Northern California and Amazon S3 US Standard Regions) will be charged at Internet Data Transfer rates on both sides of the transfer.

For S3 pricing information, please visit the pricing section on the S3 detail page.

Q: Why do prices vary depending on which Amazon S3 Region I choose?

We charge less where our costs are less. For example, our costs are lower in the US Standard Region than in the US West (Northern California) Region.

Q: How will I be charged and billed for my use of Amazon S3?

There are no set-up fees or commitments to begin using the service. At the end of the month, your credit card will automatically be charged for that month’s usage. You can view your charges for the current billing period at any time on the Amazon Web Services web site, by logging into your Amazon Web Services account, and clicking “Account Activity” under “Your Web Services Account”.

With the AWS Free Usage Tier*, you can get started with Amazon S3 for free in all regions except the AWS GovCloud Region. Upon sign-up, new AWS customers receive 5 GB of Amazon S3 standard storage, 20,000 Get Requests, 2,000 Put Requests, 15GB of data transfer in, and 15GB of data transfer out each month for one year.

Amazon S3 charges you for the following types of usage:
Note: The calculations below assume there is no AWS Free Tier in place.

Storage Used:

Amazon S3 storage pricing is summarized on the Amazon S3 Pricing Chart.

The volume of storage billed in a month is based on the average storage used throughout the month. This includes all object data and metadata stored in buckets that you created under your AWS account. We measure your storage usage in “TimedStorage-ByteHrs,” which are added up at the end of the month to generate your monthly charges.

Storage Example:
Assume you store 100GB (107,374,182,400 bytes) of standard Amazon S3 storage data in your bucket for 15 days in March, and 100TB (109,951,162,777,600 bytes) of standard Amazon S3 storage data for the final 16 days in March.

At the end of March, you would have the following usage in Byte-Hours:
Total Byte-Hour usage
= [107,374,182,400 bytes x 15 days x (24 hours / day)] + [109,951,162,777,600 bytes x 16 days x (24 hours / day)] = 42,259,901,212,262,400 Byte-Hours.

Let’s convert this to GB-Months:
42,259,901,212,262,400 Byte-Hours x (1 GB / 1,073,741,824 bytes) x (1 month / 744 hours) = 52,900 GB-Months

This usage volume crosses three different volume tiers. The monthly storage price is calculated below assuming the data is stored in the US Standard Region:
1 TB Tier: 1024GB x $0.125 = $128.00
1 TB to 50 TB Tier: 50,176 GB (49×1024) x $0.110 = $5,519.36
50 TB to 450 TB Tier: 1,700 GB (remainder) x $0.095 = $161.50

Total Storage Fee = $128.00 + $5,519.36 + $161.50 = $5,808.86

Network Data Transferred In:

Amazon S3 Data Transfer In pricing is summarized on the Amazon S3 Pricing Chart.

This represents the amount of data sent to your Amazon S3 buckets. Data Transfer is $0.000 per GB for buckets in the US Standard, US West (Oregon), US West (Northern California), EU (Ireland), Asia Pacific (Singapore), Asia Pacific (Tokyo), South America (Sao Paulo), and AWS GovCloud (US) Regions.

Network Data Transferred Out:

Amazon S3 Data Transfer Out pricing is summarized on the Amazon S3 Pricing Chart.

Data Transfer Out pricing rate tiers take into account your aggregate Data Transfer Out within a given region across Amazon EC2, Amazon S3, Amazon RDS, Amazon SimpleDB, Amazon SQS, Amazon SNS and Amazon VPC. For Amazon S3, this charge applies whenever data is read from any of your buckets.

Data Transfer Out Example:
Assume you transfer 1TB of data out of Amazon S3 from the US Standard Region every day for a given 31-day month. Assume you also transfer 1TB of data out of an Amazon EC2 instance from the same region over the same 31-day month.

Your aggregate Data Transfer would be 62 TB (31 TB from Amazon S3 and 31 TB from Amazon EC2). This equates to 63,488 GB (62 TB * 1024 GB/TB).

This usage volume crosses three different volume tiers. The monthly Data Transfer Out fee is calculated below assuming the Data Transfer occurs in the US Standard Region:
10 TB Tier: 10,240 GB (10×1024 GB/TB) x $0.120 = $1,228.80
10 TB to 50 TB Tier: 40,960 GB (40×1024) x $0.090 = $3,686.40
50 TB to 150 TB Tier: 12,288 GB (remainder) x $0.070 = $860.16

Total Data Transfer Out Fee = $1,228.80+ $3,686.40 + $860.16= $5,775.36

Requests:

Amazon S3 Request pricing is summarized on the Amazon S3 Pricing Chart.

Request Example:
Assume you transfer 10,000 files into Amazon S3 and transfer 20,000 files out of Amazon S3 each day during the month of March. Then, you delete 5,000 files on March 31st.
Total PUT requests = 10,000 requests x 31 days = 310,000 requests
Total GET requests = 20,000 requests x 31 days = 620,000 requests
Total DELETE requests = 5,000×1 day = 5,000 requests

Assuming your bucket is in the US Standard Region, the Request fees are calculated below:
310,000 PUT Requests: 310,000 requests x $0.01/1,000 = $3.10
620,000 GET Requests: 620,000 requests x $0.01/10,000 = $0.62
5,000 DELETE requests = 5,000 requests x $0.00 (no charge) = $0.00

* * Your usage for the free tier is calculated each month across all regions except the AWS GovCloud Region and automatically applied to your bill – unused monthly usage will not roll over. Restrictions apply; See offer terms for more details.

Q: How am I charged for accessing Amazon S3 through the AWS Management Console?

Normal Amazon S3 pricing applies when accessing the service through the AWS Management Console. To provide an optimized experience, the AWS Management Console may proactively execute requests. Also, some interactive operations result in more than one request to the service.

Q: Do your prices include taxes?

Except as otherwise noted, our prices are exclusive of applicable taxes and duties, including VAT and applicable sales tax. For example, our prices for the Asia Pacific (Tokyo) Region are inclusive of Japan consumption tax.

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Security

Q: How secure is my data?

Amazon S3 is secure by default. Only the bucket and object owners originally have access to Amazon S3 resources they create. Amazon S3 supports user authentication to control access to data. You can use access control mechanisms such as bucket policies and Access Control Lists (ACLs) to selectively grant permissions to users and groups of users. You can securely upload/download your data to Amazon S3 via SSL endpoints using the HTTPS protocol. If you need extra security, you can use your own encryption libraries to encrypt data before storing it in Amazon S3 or use the Server Side Encryption (SSE) option provided by Amazon S3 to encrypt data stored-at-rest in Amazon S3.

Q: How can I control access to my data stored on Amazon S3?

Customers may use four mechanisms for controlling access to Amazon S3 resources: Identity and Access Management (IAM) policies, bucket policies, Access Control Lists (ACLs) and query string authentication. IAM enables organizations with multiple employees to create and manage multiple users under a single AWS account. With IAM policies, companies can grant IAM users fine-grained control to their Amazon S3 bucket or objects while also retaining full control over everything the users do. With bucket policies, companies can define rules which apply broadly across all requests to their Amazon S3 resources, such as granting write privileges to a subset of Amazon S3 resources. Customers can also restrict access based on an aspect of the request, such as HTTP referrer and IP address. With ACLs, customers can grant specific permissions (i.e. READ, WRITE, FULL_CONTROL) to specific users for an individual bucket or object. With query string authentication, customers can create a URL to an Amazon S3 object which is only valid for a limited time. For more information on the various access control policies available in Amazon S3, please refer to the Access Control topic in the Amazon S3 Developer Guide.

Q: Does Amazon S3 support data access auditing?

Yes, customers can optionally configure Amazon S3 buckets to create access log records for all requests made against it. These access log records can be used for audit purposes and contain details about the request, such as the request type, the resources specified in the request, and the time and date the request was processed.

Q: What options do I have for encrypting data stored on Amazon S3?

You can choose to encrypt your data in Amazon S3 using Server Side Encryption (SSE) or using a client library like the Amazon S3 Encryption Client. Both enable you to protect sensitive data stored on Amazon S3. If you are using a client library, you retain control of keys used to encrypt. Some customers prefer this additional control of keys; others prefer not to incur the overhead required to manage and protect keys. If you are using SSE, AWS handles key management and key protection for you. You should choose SSE if you prefer AWS to manage your keys. SSE uses one of the strongest block ciphers available, 256-bit Advanced Encryption Standard (AES-256). 256-bit is the largest key size defined for AES. Both client side encryption and Server Side Encryption are supported for objects stored in Standard Storage and Reduced Redundancy Storage (RRS). For more information on using Amazon S3 Server Side Encryption, please refer to the topic on Using Server Side Encryption in the Amazon S3 Developer Guide.

Q: How does Amazon protect SSE encryption keys?

With SSE, every protected object is encrypted with a unique key. This object key is itself encrypted by a separate master key. A new master key is issued at least monthly. Encrypted data, encryption keys and master keys are stored and secured on separate hosts for multiple layers of protection.

Q: Can I comply with EU data privacy regulations using Amazon S3?

Objects stored in the EU (Ireland) Region never leave the EU unless you transfer them out. However, it is your responsibility to ensure that you comply with EU privacy laws.

Q: Where can I find more information about security on AWS?

For more information on security on AWS please refer to our Amazon Web Services: Overview of Security Processes document.

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Data Protection

Q: How durable is Amazon S3?

Amazon S3 is designed to provide 99.999999999% durability of objects over a given year. This durability level corresponds to an average annual expected loss of 0.000000001% of objects. For example, if you store 10,000 objects with Amazon S3, you can on average expect to incur a loss of a single object once every 10,000,000 years. In addition, Amazon S3 is designed to sustain the concurrent loss of data in two facilities.

Q: How is Amazon S3 designed to achieve 99.999999999% durability?

Amazon S3 redundantly stores your objects on multiple devices across multiple facilities in an Amazon S3 Region. The service is designed to sustain concurrent device failures by quickly detecting and repairing any lost redundancy. When processing a request to store data, the service will redundantly store your object across multiple facilities before returning SUCCESS. Amazon S3 also regularly verifies the integrity of your data using checksums.

Q: What checksums does Amazon S3 employ to detect data corruption?

Amazon S3 uses a combination of Content-MD5 checksums and cyclic redundancy checks (CRCs) to detect data corruption. Amazon S3 performs these checksums on data at rest and repairs any corruption using redundant data. In addition, the service calculates checksums on all network traffic to detect corruption of data packets when storing or retrieving data.

Q: What is Versioning?

Versioning allows you to preserve, retrieve, and restore every version of every object stored in an Amazon S3 bucket. Once you enable Versioning for a bucket, Amazon S3 preserves existing objects anytime you perform a PUT, POST, COPY, or DELETE operation on them. By default, GET requests will retrieve the most recently written version. Older versions of an overwritten or deleted object can be retrieved by specifying a version in the request.

Q: Why should I use Versioning?

Amazon S3 provides customers with a highly durable storage infrastructure. Versioning offers an additional level of protection by providing a means of recovery when customers accidentally overwrite or delete objects. This allows you to easily recover from unintended user actions and application failures. You can also use Versioning for data retention and archiving.

Q: How do I start using Versioning?

You can start using Versioning by enabling a setting on your Amazon S3 bucket. For more information on how to enable Versioning, please refer to the Amazon S3 Technical Documentation.

Q: How does Versioning protect me from accidental deletion of my objects?

When a user performs a DELETE operation on an object, subsequent default requests will no longer retrieve the object. However, all versions of that object will continue to be preserved in your Amazon S3 bucket and can be retrieved or restored. Only the owner of an Amazon S3 bucket can permanently delete a version.

Q: How can I ensure maximum protection of my preserved versions?

Versioning’s MFA Delete capability, which uses multi-factor authentication, can be used to provide an additional layer of security. By default, all requests to your Amazon S3 bucket require your AWS account credentials. If you enable Versioning with MFA Delete on your Amazon S3 bucket, two forms of authentication are required to permanently delete a version of an object: your AWS account credentials and a valid six-digit code and serial number from an authentication device in your physical possession. To learn more about enabling Versioning with MFA Delete, including how to purchase and active an authentication device, please refer to the Amazon S3 Technical Documentation.

Q: How am I charged for using Versioning?

Normal Amazon S3 rates apply for every version of an object stored or requested. For example, let’s look at the following scenario to illustrate storage costs when utilizing Versioning (let’s assume the current month is 31 days long):

1) Day 1 of the month: You perform a PUT of 4 GB (4,294,967,296 bytes) on your bucket.
2) Day 16 of the month: You perform a PUT of 5 GB (5,368,709,120 bytes) within the same bucket using the same key as the original PUT on Day 1.

When analyzing the storage costs of the above operations, please note that the 4 GB object from Day 1 is not deleted from the bucket when the 5 GB object is written on Day 15. Instead, the 4 GB object is preserved as an older version and the 5 GB object becomes the most recently written version of the object within your bucket. At the end of the month:

Total Byte-Hour usage
[4,294,967,296 bytes x 31 days x (24 hours / day)] + [5,368,709,120 bytes x 16 days x (24 hours / day)] = 5,128,190,951,424 Byte-Hours.

Conversion to Total GB-Months
3,942,779,977,728 Byte-Hours x (1 GB / 1,073,741,824 bytes) x (1 month / 744 hours) = 6.419 GB-Months

The storage fee is calculated below assuming data is stored in the US Standard Region:
0 to 1 TB Tier: 6.419GB x $0.125 = $0.80

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Reduced Redundancy Storage (RRS)

Q: What is RRS?

Reduced Redundancy Storage (RRS) is a new storage option within Amazon S3 that enables customers to reduce their costs by storing non-critical, reproducible data at lower levels of redundancy than Amazon S3’s standard storage. RRS provides a lower cost, less durable, highly available storage option that is designed to sustain the loss of data in a single facility.

Q: Why would I choose to use RRS?

RRS is ideal for non-critical or reproducible data. For example, RRS is a cost-effective solution for sharing media content that is durably stored elsewhere. RRS also makes sense if you are storing thumbnails and other resized images that can be easily reproduced from an original image.

Q: What is the durability of Amazon S3 when using RRS?

RRS is designed to provide 99.99% durability of objects over a given year. This durability level corresponds to an average annual expected loss of 0.01% of objects. For example, if you store 10,000 objects using the RRS option, you can on average expect to incur an annual loss of a single object (i.e. 0.01% of 10,000 objects). This annual loss represents an expected average and does not guarantee the loss of 0.01% of objects in a given year.

The RRS option stores objects on multiple devices across multiple facilities, providing 400 times the durability of a typical disk drive, but does not replicate objects as many times as standard Amazon S3 storage, and thus is even more cost effective. In addition, RRS is designed to sustain the loss of data in a single facility.

Q: How do I know if I lose an RRS object?

If an RRS object has been lost, Amazon S3 will return a 405 error on requests made to that object. Amazon S3 also offers notifications for Reduced Redundancy Storage (RRS) object loss. Customers can configure their bucket so that when Amazon S3 detects the loss of an RRS object, a notification will be sent through Amazon Simple Notification Service (SNS). This enables customers to replace lost RRS objects.

Q: How do I specify that I want to store my data using RRS?

All objects in Amazon S3 have a storage class setting. The default setting is STANDARD. You can use an optional header on a PUT request to specify the setting REDUCED_REDUNDANCY.

Q: Are my RRS objects backed with the Amazon S3 Service Level Agreement?

Yes, you can utilize RRS without sacrificing the availability of your data. RRS is backed with the Amazon S3 Service Level Agreement, providing financial penalties if availability is less than 99.9% in a given month.

Q: How will my performance be impacted as a result of using RRS?

You should expect the same latency and throughput as standard Amazon S3 storage when using RRS.

Q: How am I charged for using RRS?

Storage pricing for RRS can be found on the pricing section of the Amazon S3 detail page. Standard Amazon S3 rates apply for bandwidth and requests.