Offline-first Mac/iOS apps are finally catching up. A wave of releases proves you can run AI, image work, and prompts entirely on-device, boosting speed, privacy, and reliability. From Fuse Caption Studio for on-device captions to RasterFox for local image optimization, the trend is clear. Plus on-device tools like My Prompt Tester and Apple On-Device OpenAI API point to a privacy-forward future.[1][2][5][4]
Fuse Caption Studio runs entirely on-device, delivering fast, private subtitles with no cloud uploads.[1]
RasterFox, written in Swift and Rust, runs locally with Rust-powered optimization and no Electron. It handles PNG, JPEG, WebP, and AVIF, supports batch processing, and lets you compare originals with optimized results in a synced view. It offers Safe replace options, presets, and advanced tweaks. Updates have arrived: Version 1.0.5 lowers the lifetime Pro price, and Version 1.1.0 adds resizing, EXIF support, clipboard tweaks, and more.[2]
Offline watermark workflows for macOS came up in discussions about batch-watermarking large photo sets (300–800 images), with references to GUI and CLI options like Retrobatch for privacy-focused, offline pipelines.[3]
Apple On-Device OpenAI API presents an OpenAI-compatible server on macOS that runs on-device Foundation Models, with endpoints like /v1/chat/completions and streaming, giving a cloud-free chat-style surface.[4]
My Prompt Tester is a fast tool to test Apple Intelligence prompts and instructions, copy complete prompt+response histories, and sync via iCloud across macOS, iOS, and iPadOS.[5]
References
Fuse Caption Studio - The first on-device AI captioning tool that is fast, private, and incredibly accurate.
New macOS app Fuse Caption Studio launches; on-device subtitles, privacy; giveaways; user questions on languages, karaoke, pricing, and model management.
View sourceRasterFox - an Image Optimizer built for Web Developers
RasterFox Mac image optimizer launches; fast, feature-rich; compares with ImageOptim and Clop; pricing changes; CLI available.
View sourceLooking for a reliable way to batch-watermark large photo sets (macOS, offline preferred)
Discussion on macOS offline batch watermarking tools; mentions Retrobatch and Photomill as possible workflows, seeking logo text watermark edge padding
View sourceApple On-Device OpenAI API: Run ChatGPT-style models locally via Apple Foundation Models
Mac on-device OpenAI API uses Foundation Models; local chat API; interesting but too complicated for non-devs, with pricing unclear currently.
View sourceMy Prompt Tester - to test Apple Intelligence prompts and instructions.
New app My Prompt Tester tests Apple Intelligence prompts; on-device; free; macOS, iOS, iPadOS; history synced via iCloud.
View source