Documentation
Support guides
Account management
User access and control
These articles describe how to manage users with permission to access to your account.
- Adding and deleting user accounts
- Configuring user roles and permissions
- Email and password changes
- Merging accounts
- Setting up single sign-on (SSO)
Account management and security
These articles describe how to manage account access and security.
- Account lockouts
- Changing your account's company name
- Enabling an IP whitelist for account logins
- Enabling and disabling two-factor authentication
- Finding and managing your account info
- Using API tokens
Account types and billing
These articles describe Fastly's billing and payment plans and how to make adjustments to your billing information.
Basic setup
Basic setup
These articles provide basic instructions for getting started with Fastly services.
- Adding CNAME records
- Getting started with Fastly
- Glossary of terms
- IPv6 support
- Sign up and create your first service
- Working with services
Basic configuration
These articles provide basic instructions for configuring Fastly services after getting started.
- Adding or modifying headers on HTTP requests and responses
- Caching configuration best practices
- Connecting to origins
- Creating and customizing a robots.txt file
- Creating error pages with custom responses
- Enabling automatic gzipping
- How request settings are applied
- Manipulating the X-Forwarded-For header
- Overriding caching defaults based on a backend response
- Removing headers from backend response
- Responses tutorial
- Setting Content Type based on file extension
- Specifying an override host
- Testing setup before changing domains
- Using Fastly with apex domains
- Working with domains
- Working with health checks
Basic concepts
These articles describe the most basic concepts of Fastly's CDN services.
- About the web interface controls
- Content and its delivery
- Fastly POP locations
- How caching and CDNs work
- How Fastly's CDN Service works
- HTTP status codes cached by default
- Self-provisioned Fastly services
Developer's tools
API Caching
These articles describe how to cache responses from an API.
Conditions
These articles define conditions in VCL and the Fastly web interface.
Edge Dictionaries
These articles describe how to move rapid key/value pair decision logic to the edge.
- About Edge Dictionaries
- Creating and manipulating dictionary items
- Creating and using Edge Dictionaries
- Private Edge Dictionaries
Purging
These articles describe how to purge by affiliation, by URL, or even purge all of your site's cached content for a full refresh.
- Authenticating URL purge requests via API
- Getting started with surrogate keys
- Logging purge requests
- Setting Surrogate-Key headers based on a URL
- Setting Surrogate-Key headers for Amazon S3 origins
- Single purges
- Soft purges
- Wildcard purges
VCL tutorials
These articles provide information about how to use VCL to customize Fastly services.
- Accept-Language header VCL features
- Authenticating before returning a request
- Conditionally changing a URL
- Creating location-based tagging
- Custom responses that don't hit origin servers
- Delivering different content to different devices
- Guide to VCL
- Isolating header values without regular expressions
- Manipulating the cache key
- Overriding which IP address the geolocation features use
- Response Cookie handling
- Setting up redundant origin servers
- Support for the Edge-Control header
- Understanding the different PASS action behaviors
- VCL regular expression cheat sheet
Tutorials
These articles provide examples of some of the deeper technology Fastly makes available.
Diagnostics and performance
Streaming logs
These articles describe Fastly's support for syslog and syslog-compatible log streaming providers as well as other methods of sending logging information.
- Changing log line formats
- Changing where log files are written
- Custom log formats
- Encrypting logs
- Log streaming: Amazon S3
- Log streaming: Cloud Files
- Log streaming: Datadog
- Log streaming: DigitalOcean Spaces
- Log streaming: FTP
- Log streaming: Google BigQuery
- Log streaming: Google Cloud Storage
- Log streaming: Log Shuttle
- Log streaming: LogDNA
- Log streaming: Logentries
- Log streaming: Loggly
- Log streaming: Heroku's Logplex
- Log streaming: OpenStack
- Log streaming: Papertrail
- Log streaming: Scalyr
- Log streaming: Sumo Logic
- Log streaming: Syslog
- Setting up remote log streaming
- Useful conditions for logging
- Useful variables to log
Debugging
These articles describe debugging techniques that help you gain insights into your service configurations.
- Browser recommendations when using the Fastly web interface
- Changing connection timeouts to your origin
- Checking cache
- Common 503 errors
- Common service and domain errors
- Debugging with mtr
- Debugging with WebPageTest
- Error 1000 with CloudFlare DNS
- Fastly's network status
- Google Pagespeed module errors
- Googlebot crawl stats
- Loop detection
- Resource limits
- Temporarily disabling caching
- TLS certificate errors
- TLS origin configuration messages
- Using GET instead of HEAD for command line caching tests
Performance tuning
These articles describe how to tune the performance of Fastly's services beyond standard configuration methods.
- Changing origins based on user location
- Checking multiple backends for a single request
- Controlling caching
- Enabling cross-origin resource sharing (CORS)
- Enabling global POPs
- Failover configuration
- Fixing cross-domain errors
- Generating HTTP redirects at the edge
- HTTP/2 server push
- Improving caching performance with large files
- Load-balancing configuration
- Maintaining separate HTTP and HTTPS requests to origin servers
- Making query strings agnostic
- Request collapsing
- Routing assets to different origins
- Serving stale content
- Shielding
- Tracking your origin's name, IP, and port
- Understanding cache HIT and MISS headers with shielded services
- Understanding the X-Timer header
- Using edge side includes (ESI)
Security
Access control lists
These articles describe how to restrict access to resources by allowing or blocking IP addresses with access control lists (ACLs).
- About ACLs
- Manually creating access control lists
- Working with ACLs using the API
- Working with ACLs using the web interface
Monitoring and testing
These articles provide information about monitoring and testing the security of your services behind Fastly.
Securing communications
These articles describe how to set up TLS certificates with Fastly services.
- Accessing Fastly's IP ranges
- Domain validation for TLS certificates
- Enabling HSTS through Fastly
- Forcing a TLS redirect
- Managing domains on TLS certificates
- Setting up free TLS
- Support for App Transport Security
- TLS key and certificate replacement
- TLS termination
Web Application Firewall
These articles provide information about the Fastly Web Application Firewall (WAF) security service.
- About the Fastly WAF dashboard
- Fastly WAF logging
- Fastly WAF rule set updates and maintenance
- Managing the Fastly WAF
- Web Application Firewall (WAF)
Migrations and integrations
Migrations
These articles describe migrations between Fastly services and non-Fastly services.
Integrations
These articles describe how non-Fastly services interoperate with Fastly.
- Acquia Cloud
- Amazon S3
- DigitalOcean Spaces
- Google Cloud Storage
- Google Compute Engine
- Microsft Azure Blob Storage
- PerimeterX Bot Defender
Load Balancer
Dynamic Servers
These articles describe how to use Dynamic Servers to dynamically distribute and direct incoming requests to a group of servers.
- About Dynamic Servers
- Creating and using pools with Dynamic Servers
- Creating and using server entries with Dynamic Servers
Tutorials
These articles explain how to use the Fastly Load Balancer.
Image optimization
Setup and use
These articles provide basic instructions for setting up and beginning to use the Fastly Image Optimizer.
- Image optimization VCL boilerplate
- Purging optimized images
- Serving images
- Serving responsive images
- Setting up image optimization
Examples
These articles provide examples of the Fastly Image Optimizer API in use.
- Automating optimization
- Controlling image quality
- Cropping images
- Reorienting images
- Resizing images
- Trimming images
Online video streaming
Live streaming
These articles describe setup and configuration guidelines for live stream delivery.
On-the-fly packaging
These articles describe how to deliver packaged, adaptive bitrate video on-demand from a single source format.
Compliance and law
Compliance and Law FAQ
This FAQ answers questions we often get about our Terms of Service, our privacy statements, our documentation, our Acceptable Use Policy, and how they all work together. It does not replace any of those, nor is it legally binding on its own.
Compliance
These articles provide information about the processes and safeguards we follow to protect your data.
Security measures
These articles provide information about the administrative, physical, and technical safeguards that protect the Fastly CDN service.
Third-party technology
These articles provide information about third-party technology and services incorporated into the Fastly CDN service.
Cloud-hosted products
These articles provide information about Fastly products that may use third-party infrastructure to process or store content.
Related offerings
These service level agreements offered by Fastly provide information to customers based on the nature of their agreement with Fastly and the Fastly products they have purchased.
Sub-processors
This legal statement provides information about sub-processors in connection with the provision of the Fastly Services.
Translations
This legal statement provides information about the primary language for Fastly service guides.
Archives
These articles provide links to the historical versions of our documentation, terms, and policies.
Products and services
Detailed product descriptions
These articles provide detailed, plain English descriptions of Fastly's products.
- About Fastly's Application Programming Interface (API)
- About Fastly's Cloud Accelerator
- About Fastly's Customer Support
- About Fastly's Full-site Delivery features
- About Fastly's Media Shield
- About Fastly's On-the-Fly Packaging service
- About Fastly's Real-Time Log Streaming features
- About Fastly's Video Caching service
- Always-on DDoS mitigation
- Assurance Services
- DDoS Protection and Mitigation Service and SLA
- HIPAA and caching PHI
- Legacy Platinum Support and SLA
- Legacy Premium Support and SLA
- Logging Insights Package
- PCI-compliant caching
- Performance Optimization Package
- Platform TLS Certificate Management Service
- Professional Services
- Service availability SLA
- Subscriber Provided Prefix
- Support description and SLA
- Technical Account Management
- TLS service options
- WAF Management Package
Fastly product lifecycle
Fastly releases or retires its products and features as detailed below.
VCL
Cryptographic
Functions
- digest.awsv4_hmac()
- digest.base64_decode()
- digest.base64()
- digest.base64url_decode()
- digest.base64url_nopad_decode()
- digest.base64url_nopad()
- digest.base64url()
- digest.hash_crc32()
- digest.hash_crc32b()
- digest.hash_md5()
- digest.hash_sha1()
- digest.hash_sha224()
- digest.hash_sha256()
- digest.hash_sha384()
- digest.hash_sha512()
- digest.hmac_md5_base64()
- digest.hmac_md5()
- digest.hmac_sha1_base64()
- digest.hmac_sha1()
- digest.hmac_sha256_base64()
- digest.hmac_sha256()
- digest.rsa_verify()
- digest.secure_is_equal()
- digest.time_hmac_md5()
- digest.time_hmac_sha1()
- digest.time_hmac_sha256()
Date and time
Functions
Variables
- now.sec
- now
- time.elapsed.msec_frac
- time.elapsed.msec
- time.elapsed.sec
- time.elapsed.usec_frac
- time.elapsed.usec
- time.elapsed
- time.end.msec_frac
- time.end.msec
- time.end.sec
- time.end.usec_frac
- time.end.usec
- time.end
- time.start.msec_frac
- time.start.msec
- time.start.sec
- time.start.usec_frac
- time.start.usec
- time.start
- time.to_first_byte
Geolocation
Variables
- client.as.name
- client.as.number
- client.geo.area_code
- client.geo.city.ascii
- client.geo.city.utf8
- client.geo.city
- client.geo.conn_speed
- client.geo.continent_code
- client.geo.country_code
- client.geo.country_code3
- client.geo.country_name.ascii
- client.geo.country_name.ascii
- client.geo.country_name
- client.geo.gmt_offset
- client.geo.latitude
- client.geo.longitude
- client.geo.metro_code
- client.geo.postal_code
- client.geo.region
- server.datacenter
- server.region
Miscellaneous
Functions
- cstr_escape()
- http_status_matches()
- if()
- json.escape()
- std.atoi()
- std.ip()
- std.ip2str()
- std.str2ip()
- std.strlen()
- std.strstr()
- std.strtol()
- std.tolower()
- std.toupper()
- subfield()
- urldecode()
- urlencode()
Variables
- bereq.url.basename
- bereq.url.dirname
- bereq.url.qs
- bereq.url
- beresp.backend.ip
- beresp.backend.name
- beresp.backend.port
- beresp.grace
- beresp.hipaa
- beresp.pci
- client.port
- client.requests
- req.grace
- req.http.host
- req.is_ipv6
- req.restarts
- req.topurl
- req.url.basename
- req.url.dirname
- req.url.ext
- req.url.path
- req.url.qs
- req.url
- stale.exists
Query string manipulation
Functions
- boltsort.sort()
- querystring.add()
- querystring.clean()
- querystring.filter_except()
- querystring.filter()
- querystring.filtersep()
- querystring.globfilter_except()
- querystring.globfilter()
- querystring.regfilter_except()
- querystring.regfilter()
- querystring.remove()
- querystring.set()
- querystring.sort()
Randomness
Functions
Size
Variables
- req.body_bytes_read
- req.bytes_read
- req.header_bytes_read
- resp.body_bytes_written
- resp.bytes_written
- resp.completed
- resp.header_bytes_written
TLS and HTTP/2
Functions
Variables
- fastly_info.h2.is_push
- fastly_info.h2.stream_id
- fastly_info.is_h2
- tls.client.cipher
- tls.client.ciphers_sha
- tls.client.protocol
- tls.client.servername
- tls.client.tlsexts_sha
UUID
Functions
- uuid.dns()
- uuid.is_valid()
- uuid.is_version3()
- uuid.is_version4()
- uuid.is_version5()
- uuid.oid()
- uuid.url()
- uuid.version3()
- uuid.version4()
- uuid.version5()
- uuid.x500()
Custom VCL
VCL Snippets
API
- Authentication
- Clients
- Account
- Configuration
- Purging
- Historical stats
- Real-time analytics
- Remote logging
- Utilities
- Image optimization
- Web Application Firewall
- Dynamic Servers