image-optimizer

Open source alternative to TinyPNG, ShortPixel, Cloudinary, Kraken.io and ImageKit

924 stars
MIT
Active this week
Last commit 7 days ago

Last verified Oct 20, 2026

Optimize JPEG, PNG, GIF, and SVG files locally with a free desktop app. No uploads, no subscription fees, files never leave your machine.

Visit website GitHub924

Read the full breakdownWho it is for, how it works, trade-offs and the FAQ

who it's for

Who image-optimizer is for#

Designers preparing assets for web handoff

Export a folder of assets from Figma or Sketch, drop it into Image Optimizer, and get compressed files without touching a command line or hitting an API quota. The before/after preview lets you confirm visual quality before handing files to an engineer.

Skip if:

You need to preserve raw source files exactly as exported. Image Optimizer can replace originals if the in-place output mode is selected; use the output folder or .min suffix option to avoid overwriting source files.

Frontend developers optimizing images before a commit

Run Image Optimizer on a directory of images before adding them to a repository. The app processes JPEG, PNG, GIF, and SVG in one pass and writes results to a separate folder, which makes the diff clean and the file size reduction visible in the pull request.

Skip if:

Your project already uses automated image optimization in the build pipeline (Next.js Image, vite-plugin-imagemin, or similar). A manual pass on top of build-time optimization may produce diminishing returns.

Content teams compressing media before CMS uploads

Compress a batch of product images, blog photos, or marketing assets before uploading to a CMS. Keeping assets below a target file size without a paid cloud plan is the core use case: drop a folder, set a quality level, and upload the results.

Skip if:

Your CMS handles optimization automatically on upload (Cloudinary, Sanity with image pipeline, WordPress with a compression plugin). In that case, a local pre-optimization pass is redundant.

the problem

The problem it solves#

Every image that ships to a user over the web costs bandwidth. Unoptimized images slow page loads, hurt Core Web Vitals scores, and inflate hosting bills. The standard response is to reach for an online service like TinyPNG or ShortPixel, but those tools have real costs: a free tier that runs out quickly, subscription fees that scale with usage, and the fact that your files leave your machine and land on someone else's servers.

For designers and developers who work with sensitive assets (unreleased designs, client work, private product photos) or who process images in volume, the cloud-service model is a poor fit. Command-line tools like mozjpeg and pngquant do the job for free, but they require environment setup and offer no visual way to review per-file results before committing to an output folder.

how image-optimizer solves it

How it solves it#

Batch folder processing with recursive scanning

Drop individual files or entire folders and the app processes everything inside, including nested subfolders. Per-file results show original size, optimized size, savings percentage, and elapsed time so you can review what changed before committing to an output path.

Four format types with dedicated optimizers per format

JPEG files are compressed with mozjpeg, PNG files with pngquant, GIF files with gifsicle, and SVG files with SVGO. Each optimizer is purpose-built for its format, which typically achieves better compression than a single general-purpose tool would across all four types.

WebP conversion for JPEG and PNG

Convert JPEG and PNG files to WebP format in the same workflow, powered by cwebp. WebP files are typically 25-35% smaller than their JPEG or PNG equivalents at equivalent visual quality, which directly reduces page weight for web projects.

Before/after preview with adjustable quality

An interactive before/after preview lets you compare the original and optimized image visually before writing results. JPEG and PNG quality levels are adjustable before running a job, giving you control over the compression trade-off for each batch.

Flexible output: suffix, replace in place, or output folder

Write optimized files to a configurable output folder, add a .min suffix to preserve originals alongside the compressed versions, or replace source files in place. A reveal-in-Finder/Explorer option opens the output location directly after processing completes.

strengths · trade-offs

Strengths and trade-offs#

Strengths

Local processing: files never leave your machineAll compression runs on your local CPU using bundled optimizer binaries. No network requests, no file uploads, no third-party servers. For sensitive assets (unreleased designs, client work, private product images), this is a material privacy advantage over cloud services like TinyPNG or Kraken.io, which require uploading files to external servers.
MIT licensed and free with no usage limitsThe MIT license means no usage caps, no API quotas, and no subscription required. TinyPNG's free tier caps at 500 compressions per month; ShortPixel charges by credit. Image Optimizer has no such restrictions: you can process an unlimited number of files for free.
Desktop GUI with no CLI setup requiredDrag-and-drop interface for batch processing with no command-line configuration. Installers are available for macOS (Apple Silicon and Intel), Windows (NSIS installer), and Linux (Snap package), covering common developer and designer setups without environment configuration.

Trade-offs

-No API or scripting interface for automationImage Optimizer is a GUI desktop application with no CLI, API, or plugin interface. You cannot integrate it into a CI/CD pipeline, a build script, or an automated upload workflow. Teams that need image optimization as part of a programmatic process should use the underlying tools directly (mozjpeg, pngquant, SVGO, cwebp) or a service with an API.
-No CDN, media management, or delivery featuresUnlike Cloudinary or ImageKit, this tool only optimizes files on disk. It does not upload assets to a CDN, generate responsive image variants, or provide a URL for dynamic resizing. Teams that need those capabilities still need a cloud media service alongside this tool, or instead of it.

versus alternatives

image-optimizer vs alternatives#

Image Optimizer vs TinyPNG

TinyPNG is the most widely used online image compression tool. Both tools compress JPEG and PNG files, but they operate on different models.

Feature	Image Optimizer	TinyPNG
License	MIT	Proprietary
Processing	Local (no upload)	Cloud (files uploaded)
WebP conversion	Yes	Yes (API only)
Free tier	Unlimited (local)	500 compressions/month
API for automation	No	Yes ($25+/month)
Batch folder processing	Yes	Paid API only
Formats	JPEG, PNG, GIF, SVG	JPEG, PNG, WebP

Image Optimizer wins when privacy matters or when you process images in volume without wanting to pay per compression. TinyPNG's advantage is its API: if you need image compression integrated into a build pipeline or a CMS upload workflow, TinyPNG is a better fit than a GUI application with no scripting interface.

Image Optimizer vs ShortPixel

ShortPixel is a subscription-based service with a cloud API, a WordPress plugin, and AVIF output support.

Feature	Image Optimizer	ShortPixel
License	MIT	Proprietary
Processing	Local	Cloud
AVIF output	No	Yes
CDN delivery	No	Yes (paid plan)
WordPress integration	No	Yes (plugin)
Cost	Free	From $4.99/month

ShortPixel is the better choice for teams running WordPress or needing AVIF format support. Image Optimizer is the better choice when you want zero subscription cost, local processing, and a simple desktop workflow.

Image Optimizer vs Cloudinary

Cloudinary is a cloud media management platform that handles storage, CDN delivery, dynamic transformation, and responsive image generation alongside compression. The two tools serve different purposes.

Image Optimizer is a local batch compressor for files you already have on disk. Cloudinary is an end-to-end media pipeline for files you want to serve dynamically from a CDN. Teams that need URL-based resizing, format conversion on request, or programmatic media management should use Cloudinary. Teams that need to reduce file sizes before uploading to any destination can use Image Optimizer at no cost.

tech stack · detected from GitHub

What it's built on#

Languages: JavaScriptTypeScript
Frameworks: Vue
Tooling: SVGO

frequently asked

FAQ#

Is Image Optimizer free to use?

Yes. Image Optimizer is MIT licensed and free with no usage limits. Download the installer for macOS, Windows, or Linux from the GitHub Releases page and run it without any subscription, account, or API key.

Does Image Optimizer upload my files to the internet?

No. All compression runs locally using bundled optimizer binaries (mozjpeg, pngquant, gifsicle, SVGO, cwebp). Your files never leave your machine, which makes this a suitable choice for sensitive or unreleased assets that should not be processed on third-party servers.

What image formats does Image Optimizer support?

JPEG, PNG, GIF, and SVG. JPEG and PNG files can also be converted to WebP during processing using cwebp. GIF files are optimized with gifsicle but cannot be converted to WebP. SVG files are optimized with SVGO.

How does Image Optimizer compare to TinyPNG?

TinyPNG is an online service that compresses files via a cloud API and has a free tier limited to 500 compressions per month, with paid plans above that. Image Optimizer is a local desktop app with no compression limits, no uploads, and no subscription. TinyPNG's API is the right choice for automating compression in a build pipeline or CMS workflow; Image Optimizer has no API and is better suited to manual batch workflows.

Can I use Image Optimizer in a CI/CD pipeline or build script?

No. Image Optimizer is a GUI application with no CLI or API. For automated pipelines, use the underlying tools directly: mozjpeg for JPEGs, pngquant for PNGs, SVGO for SVGs, and cwebp for WebP conversion. Most build tools have plugins for these (for example, vite-plugin-imagemin for Vite projects, or imagemin for Node.js scripts).

also worth a look

Similar open-source tools#

Optimo

Alternative toCloudinary

Optimize and convert images and videos using open formats

185 GitHub stars
Licence MIT

Caret

Alternative toPlasmic

Your design canvas is backed by real files in git

38 GitHub stars
Licence Apache-2.0

Fluent-Qt

Alternative toQFluentWidgets

Fluent UI component library for Qt Widgets in C++17 and Python

174 GitHub stars
Licence MIT

Neon-Vision-Editor

Alternative toBBEdit

Native Apple text and Markdown editor with safe file sync

451 GitHub stars
Licence Apache-2.0

Onlook

Alternative toFigma

Visual React editor where every design change writes real code

26,928 GitHub stars
Licence Apache-2.0

screenshot-to-code

Alternative toGoogle Stitch

Turn any design screenshot into clean, working code with AI

80,568 GitHub stars
Licence MIT

by category

Open source tools in these categories#

196

Featured

rakazo

Alternative toGrok Bot

AI teammates you own: your keys, your model, your machine.

4,904 GitHub stars
Licence Apache-2.0
#AI Agents

Inbox Zero

Alternative toSuperhuman

AI email assistant that drafts replies and clears your inbox

12,712 GitHub stars
Licence AGPL-3.0
#Email

Omnara

Alternative toClaude Managed Agents

Open-source agent deployment API. Self-host or use Omnara Cloud.

2,957 GitHub stars
Licence Apache-2.0
#AI Agents

Feature your project

The projects we add and every new guide. Free, unsubscribe any time.

Find open source alternatives to paid software

Image Optimizer vs TinyPNG

TinyPNG is the most widely used online image compression tool. Both tools compress JPEG and PNG files, but they operate on different models.

Feature	Image Optimizer	TinyPNG
License	MIT	Proprietary
Processing	Local (no upload)	Cloud (files uploaded)
WebP conversion	Yes	Yes (API only)
Free tier	Unlimited (local)	500 compressions/month
API for automation	No	Yes ($25+/month)
Batch folder processing	Yes	Paid API only
Formats	JPEG, PNG, GIF, SVG	JPEG, PNG, WebP

Image Optimizer vs ShortPixel

ShortPixel is a subscription-based service with a cloud API, a WordPress plugin, and AVIF output support.

Feature	Image Optimizer	ShortPixel
License	MIT	Proprietary
Processing	Local	Cloud
AVIF output	No	Yes
CDN delivery	No	Yes (paid plan)
WordPress integration	No	Yes (plugin)
Cost	Free	From $4.99/month

Who image-optimizer is for#

Designers preparing assets for web handoff

Skip if:

Frontend developers optimizing images before a commit

Skip if:

Content teams compressing media before CMS uploads

Skip if:

The problem it solves#

How it solves it#

Batch folder processing with recursive scanning

Four format types with dedicated optimizers per format

WebP conversion for JPEG and PNG

Before/after preview with adjustable quality

Flexible output: suffix, replace in place, or output folder

Strengths and trade-offs#

Strengths

Trade-offs

image-optimizer vs alternatives#

Image Optimizer vs TinyPNG

Image Optimizer vs ShortPixel

Image Optimizer vs Cloudinary

What it's built on#

FAQ#

Similar open-source tools#

Open source tools in these categories#

Web Development

Design & Creative

Developer Tools

Find open source alternatives to paid software

Who image-optimizer is for#

Designers preparing assets for web handoff

Skip if:

Frontend developers optimizing images before a commit

Skip if:

Content teams compressing media before CMS uploads

Skip if:

The problem it solves#

How it solves it#

Batch folder processing with recursive scanning

Four format types with dedicated optimizers per format

WebP conversion for JPEG and PNG

Before/after preview with adjustable quality

Flexible output: suffix, replace in place, or output folder

Strengths and trade-offs#

Strengths

Trade-offs

image-optimizer vs alternatives#

Image Optimizer vs TinyPNG

Image Optimizer vs ShortPixel

Image Optimizer vs Cloudinary

What it's built on#

FAQ#

Similar open-source tools#

Open source tools in these categories#

Web Development

Design & Creative

Developer Tools

Find open source alternatives to paid software