An ARN's service and resource-type fields tell you what kind of thing you are looking at, but only if you already know AWS's naming conventions well enough to read them — that iam + role means an IAM Role, that lambda + function means a Lambda Function, that sqs with no separate resource type at all means an SQS Queue. ARN to Resource Type Identifier does that translation for you: paste an ARN, and it parses out the service and resource-type fields, then matches that combination against a curated table of common AWS resource types to hand back a plain-English label.
The lookup table covers roughly thirty combinations spanning the services most commonly seen in day-to-day AWS work: IAM roles, users, groups, managed policies and instance profiles; Lambda functions and layers; EC2 instances, volumes, security groups, VPCs, subnets and snapshots; DynamoDB tables; SNS topics and SQS queues; KMS keys and aliases; RDS database instances and Aurora clusters; Secrets Manager secrets; SSM parameters; CloudWatch Logs log groups; CloudFormation stacks; ECS clusters, task definitions and services; EKS clusters; Step Functions state machines; API Gateway resources; CloudFront distributions; Route 53 hosted zones; CodePipeline pipelines; EventBridge rules; and load balancers. Several services — S3, SNS, SQS, and a few others — have no separate resource-type segment in their ARNs at all, since the resource id alone identifies the thing (a bucket name, a topic name, a queue name); the tool accounts for that by matching on an empty resource-type field for those services rather than expecting one that does not exist.
What makes the honesty of this tool worth spelling out is what it does when a combination is not in the table: it says so explicitly, rather than making a plausible-sounding guess. An ARN for a genuinely obscure or newer AWS service, or one with a resource-type spelling the table has not been extended to cover yet, comes back labeled as unrecognized, alongside the raw service and resource-type strings the parser actually extracted — so you always see the real underlying data even when the friendlier label is not available. That is a deliberate design choice: a resource-type identifier that guesses wrong is worse than one that admits its coverage is limited.
The matching itself only looks at the resource-type segment, not the full resource id, which means it correctly identifies the resource kind even when the specific id looks unusual, has an odd length, or does not follow the typical naming pattern for that resource — the label describes what kind of thing the ARN points to, not whether that particular instance is well-formed (that is a job for the ARN Validator instead). Likewise, this tool has no connection to your AWS account and cannot confirm that the specific resource named actually exists; it works purely from the shape of the ARN text you paste in.
This is a small companion to the ARN Parser, useful anywhere you are staring at an unfamiliar ARN — in a CloudTrail event, an error message, a colleague's Slack message — and want to know at a glance what kind of AWS resource it names, without memorizing every service's resource-type conventions yourself. Parsing and identification both happen locally; the ARN, and any account id it contains, never leaves your browser.