An S3 client that lives next to your databases.
Mongrel is a desktop S3 client for Amazon S3 and S3-compatible stores. Browse prefixes as folders, resume multipart uploads, copy a presigned GET URL, and keep secret keys in the OS keychain — in the same app as FTP, WebDAV, Azure Blob, SMB, terminals, and 30+ database engines.
Windows x64 and ARM64 · macOS Apple silicon · Linux x86-64
// Connections → File Transfer → S3
Point at Amazon S3 or a compatible endpoint.
Provider presets fill Amazon S3 (blank endpoint) or DigitalOcean Spaces (https://region.digitaloceanspaces.com, TLS required). Custom / other is for MinIO, Cloudflare R2, Backblaze B2, and Wasabi. Test Connection lists the bucket or prefix once, then Save. File Manager / is the optional path prefix.
// What ships
Object storage with a real file manager.
Amazon S3 without a custom host
Leave the endpoint blank. Mongrel uses the SDK regional resolver, including us-east-1 on s3.us-east-1.amazonaws.com, and signs SigV4 with the bucket region.
S3-compatible stores
DigitalOcean Spaces, MinIO, Cloudflare R2, Backblaze B2, and Wasabi use a service HTTPS URL. Spaces locks TLS on and prefers virtual-hosted Auto.
The same File Manager
S3 is a File Transfer profile. Dual panes, Name/Size sort, a non-selectable .. row, remembered local folders, the Transfers drawer, and Sync this folder match FTP, WebDAV, Azure Blob, and SMB.
Multipart Resume
Files of 8 MiB or larger upload as multipart (8 MiB parts). File Manager Resume continues completed parts and Range downloads. After finalize, Mongrel re-hashes the dest (SHA-256).
Presigned GET URLs
Right-click a file and copy a time-limited GET URL. Amazon URLs use the regional virtual-hosted host. Spaces uses bucket.region.digitaloceanspaces.com unless you force path-style.
Secrets and custom CA
Secret access keys and optional STS session tokens never land on the profile, in Connection Sync, or in export. A custom CA PEM is added on top of native roots.
// Limits
What this S3 client does not pretend to be.
Mongrel is not a bucket-policy editor, CloudFront console, or Google Cloud Storage client. Native Azure Blob REST is a separate File Transfer protocol. Sync this folder compares prefixes and queues transfers; there is no sync script and no POSIX chmod on objects. Use it when you need an S3-compatible File Manager beside SSH, SQL, and Kubernetes — not as a replacement for the AWS console.
// FAQ
Frequently asked questions.
Is Mongrel an S3 client?
Yes. Connections → New Connection → File Transfer → S3 creates a standalone S3 profile. Connect or Open File Manager to browse a bucket in the same dual-pane File Manager used for FTP, WebDAV, Azure Blob, and SMB.
Which S3-compatible services work?
Amazon S3 with a blank endpoint, DigitalOcean Spaces, MinIO, Cloudflare R2, Backblaze B2, and Wasabi. Paste the S3 API host, not a CloudFront, website, or CDN URL.
Does Mongrel support path-style and virtual-hosted addressing?
Yes. Auto uses virtual-hosted style for Amazon S3 and Spaces, and path-style for other custom endpoints. Buckets whose names contain a dot always use path-style under Auto so TLS wildcards still match.
What IAM actions does a listing need?
s3:ListBucket on the bucket and prefix. Downloads and presigned URLs need s3:GetObject. Uploads, new folders, rename, and delete need s3:PutObject and s3:DeleteObject.
Can I resume an S3 transfer?
Yes. File Manager Resume continues an in-progress multipart upload from the last completed part, and continues a partial download with HTTP Range. There is no POSIX chmod or symlink. Rename is copy-then-delete. Unfinished jobs stay in the durable queue until you reopen this profile.
Are downloads locked without a license?
No. Listings, downloads, and presigned URLs stay available. Open, Test, uploads, and remote mutations require an active license or trial, and honor read-only profiles.
Related guides and comparisons
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