THE FILE FIELD GUIDE
.mlpackage

Core ML Model Package

AI & Machine Learning

MLPACKAGE packages Core ML models and associated data. ML Program separates program structure from weights and requires this package format. Extracting only a model file can omit weights; preserve the complete package.

What it is used for
Packaging Core ML models with weights/companions
What the file contains
Binary data
All sections, questions and sources

Content reviewed: · Editor:Kai

Opening steps

Choose your environment or purpose to see its steps.

Identify the model type

Retain the complete package structure.

  1. Read the publisher instructions and license; record the producer, version and purpose.
  2. Check that the complete package and internal weights/components are present.
  3. Retain the original and assemble configuration and companions in a working copy.
Inspect with Xcode/Core ML Tools

Successful loading and correct inference are separate checks.

  1. Inspect model type, inputs/outputs and deployment target in Xcode on Mac.
  2. Inspect the spec with Core ML Tools and distinguish ML Program from neural network.
  3. Separate specification inspection from prediction; Core ML Tools prediction requires macOS.
Test in the matching Apple environment

Match the input contract and compare with a reference.

  1. Match feature names/types and use the producer’s preprocessing.
  2. Run known input in a supported implementation on Mac or the target Apple device.
  3. Compare predictions with the source and measure target-device memory and latency.

Menu labels and support vary by app, OS and version. Preserve the original before making changes.

Troubleshooting by symptom

  • Weights missing: recover the complete package instead of a partial copy.
  • Older OS unsupported: check model type and deployment requirements.
  • I/O mismatch: compare specification and preprocessing.
  • Missing internal weights: check for a partial package copy or changed structure.
  • predict unavailable on Linux: specification inspection and Core ML execution have different platform requirements.
  • Image type error: compare image/array feature type, name, shape and color order.

MLPACKAGE → compatible persistence / reconvert original model

  1. Identify model type/external weights and preserve the complete original.
  2. For another format, use supported conversion from the original model and validate results/deployment target.
  3. Record deployment target, input types and precision; compare source, converted and device predictions.

ML Program cannot simply be saved/renamed to MLMODEL. Other model types such as neural networks have different persistence options.

Preserve the full package

ML Programs separate program and weights; transfer the package as one artifact and preserve its internal references.

Readable specifications do not ensure device execution; check Xcode/tool and OS requirements.

Source for these steps:Apple · Model Prediction — Core ML Tools / Apple · Convert Models to ML Programs

When predictions differ

Compare resizing, color order, normalization, names and labels against the source; record conversion precision.

Compute-unit selection depends on model and environment; verify output tolerances and actual device performance.

Source for these steps:Apple · Model Prediction — Core ML Tools / Apple · Convert Models to ML Programs

Related-format differences

Related-format differences
FormatMain roleWhat to check
MLMODELSingle Core ML modelModel type/deployment target
MLPACKAGEModel component packagePreserve internal structure
MLMODELCCompiled Core ML artifactDistinct from source model storage

Handling and security

Use trusted models and legitimate tools; do not execute unfamiliar companion scripts. Avoid exposing training/business information through public converters and check model usage/redistribution rights.

Questions and answers

Can I copy only the internal model file?

Retain the package because external weights/companions may be required.

Can I rename it to MLMODEL?

ML Program requires packaging that includes external weights.

Does packaging make it runnable on every OS?

Check deployment and Core ML runtime requirements.

Is MLPACKAGE a ZIP file?

It packages model components; renaming it as ZIP is not a supported loading workflow.

Does Mac success imply every iPhone is supported?

Inspect model type, minimum OS and operator support and test the target device.

Format facts: name, steward and MIME type
Formal name
Core ML model package
Steward / specification
Apple
MIME type
Depends on the producer or server; an extension alone does not establish a MIME type.

Primary and official sources