# resmush

[![CRAN status](https://www.r-pkg.org/badges/version/resmush)](https://CRAN.R-project.org/package=resmush) [![CRAN results](https://badges.cranchecks.info/worst/resmush.svg)](https://cran.r-project.org/web/checks/check_results_resmush.html) [![Downloads](https://cranlogs.r-pkg.org/badges/resmush)](https://CRAN.R-project.org/package=resmush) [![R-CMD-check](https://github.com/dieghernan/resmush/actions/workflows/check-full.yaml/badge.svg)](https://github.com/dieghernan/resmush/actions/workflows/check-full.yaml) [![R-hub](https://github.com/dieghernan/resmush/actions/workflows/rhub.yaml/badge.svg)](https://github.com/dieghernan/resmush/actions/workflows/rhub.yaml) [![codecov](https://codecov.io/gh/dieghernan/resmush/graph/badge.svg)](https://app.codecov.io/gh/dieghernan/resmush) [![CodeFactor](https://www.codefactor.io/repository/github/dieghernan/resmush/badge)](https://www.codefactor.io/repository/github/dieghernan/resmush) [![r-universe](https://dieghernan.r-universe.dev/badges/resmush)](https://dieghernan.r-universe.dev/resmush) [![DOI](https://img.shields.io/badge/DOI-10.32614/CRAN.package.resmush-blue)](https://doi.org/10.32614/CRAN.package.resmush) [![Project Status: Active – The project has reached a stable, usable state and is being actively developed.](https://www.repostatus.org/badges/latest/active.svg)](https://www.repostatus.org/#active) [![status](https://tinyverse.netlify.app/status/resmush)](https://CRAN.R-project.org/package=resmush) **resmush** is a **R** package that allows users to optimize and compress images using [**reSmush.it**](https://resmush.it/). reSmush.it is a free API that provides image optimization and has been implemented in [WordPress](https://wordpress.org/plugins/resmushit-image-optimizer/) and [many other tools](https://resmush.it/tools/). Some of the features of **reSmush.it** include: - Free optimization services with no API key required. - Support for both local and online images. - Supported image formats: `png`, `jpg/jpeg`, `gif`, `bmp`, `tiff`. - Maximum image size: 5 MB. - Compression using several algorithms: - [**PNGQuant**](https://pngquant.org/): Removes unnecessary chunks from `png` files while preserving a full alpha transparency. - [**JPEGOptim**](https://github.com/tjko/jpegoptim)**:** Lossless optimization based on Huffman table optimization. - [**OptiPNG**](https://optipng.sourceforge.net/): A `png` optimizer used by several online compression tools. ## Installation

Install **resmush** from [**CRAN**](https://CRAN.R-project.org/package=resmush) with: ``` r install.packages("resmush") ```

You can install the development version of **resmush** from [GitHub](https://github.com/) with: ``` r # install.packages("pak") pak::pak("dieghernan/resmush") ``` Alternatively, install **resmush** using the [r-universe](https://dieghernan.r-universe.dev/resmush): ``` r # Install resmush in R: install.packages("resmush", repos = c( "https://dieghernan.r-universe.dev", "https://cloud.r-project.org" )) ```

## Example Compressing an online `jpg` image: ``` r library(resmush) url <- paste0( "https://raw.githubusercontent.com/dieghernan/", "resmush/main/img/jpg_example_original.jpg" ) resmush_url(url, outfile = "man/figures/jpg_example_compress.jpg", overwrite = TRUE) #> ══ resmush summary ═════════════════════════════════════════════════════════════ #> ℹ Input: 1 url with size 44.2 Kb #> ✔ Success for 1 url: Size now is 44.2 Kb (was 44.2 Kb). Saved 56 bytes (0.12%). #> See result in directory 'man/figures'. ```

[

](https://raw.githubusercontent.com/dieghernan/resmush/main/img/jpg_example_original.jpg) [ Optimized file

](https://dieghernan.github.io/resmush/reference/figures/jpg_example_compress.jpg)

Original picture (top): 178.7 Kb; Optimized picture (bottom): 45 Kb (Compression: 74.8%). Click to enlarge.

The compression quality for `jpg` files can be adjusted using the `qlty` argument. However, it is recommended to keep this value above 90 to maintain good image quality. ``` r # Extreme case resmush_url(url, outfile = "man/figures/jpg_example_compress_low.jpg", overwrite = TRUE, qlty = 3 ) #> ══ resmush summary ═════════════════════════════════════════════════════════════ #> ℹ Input: 1 url with size 44.2 Kb #> ✔ Success for 1 url: Size now is 2.2 Kb (was 44.2 Kb). Saved 42 Kb (94.96%). #> See result in directory 'man/figures'. ```

[

](https://dieghernan.github.io/resmush/reference/figures/jpg_example_compress_low.jpg)

Low quality image due to a high compression rate.

All the functions return (invisibly) a dataset summarizing the process. The following example shows how this works when compressing a local file: ``` r png_file <- system.file("extimg/example.png", package = "resmush") # For the example, copy to a temporary file tmp_png <- tempfile(fileext = ".png") file.copy(png_file, tmp_png, overwrite = TRUE) #> [1] TRUE summary <- resmush_file(tmp_png, overwrite = TRUE) tibble::as_tibble(summary[, -c(1, 2)]) #> # A tibble: 1 × 6 #> src_size dest_size compress_ratio notes src_bytes dest_bytes #> #> 1 239.9 Kb 70.7 Kb 70.54% OK 245618 72356 ``` ## Other alternatives Several other **R** packages also provide image optimization tools: - **xfun** ([Xie 2024](#ref-xfun)), which includes: - `xfun::tinify()`: Similar to `resmush_file()` but uses [**TinyPNG**](https://tinypng.com/) and requires an API key. - `xfun::optipng()`: Compresses local files using **OptiPNG**, which must be installed locally. - [**tinieR**](https://jmablog.github.io/tinieR/) by [jmablog](https://jmablog.com/): An **R** interface to [**TinyPNG**](https://tinypng.com/). - [**optout**](https://github.com/coolbutuseless/optout) by [@coolbutuseless](https://coolbutuseless.github.io/): Similar to `xfun::optipng()` but with more options. Requires additional local software. | tool | CRAN | Additional software? | Online? | API Key? | Limits? | |-------------------|------|----------------------|---------|----------|-----------------------------| | `xfun::tinify()` | Yes | No | Yes | Yes | 500 files/month (free tier) | | `xfun::optipng()` | Yes | Yes | No | No | No | | **tinieR** | No | No | Yes | Yes | 500 files/month (free tier) | | **optout** | No | Yes | No | No | No | | **resmush** | Yes | No | Yes | No | Max size 5 MB | Table 1: **R** packages: Comparison of alternatives for optimizing images. | tool | png | jpg | gif | bmp | tiff | webp | pdf | |-------------------|-----|-----|-----|-----|------|------|-----| | `xfun::tinify()` | ✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ | | `xfun::optipng()` | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | **tinieR** | ✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ | | **optout** | ✅ | ✅ | ❌ | ❌ | ❌ | ❌ | ✅ | | **resmush** | ✅ | ✅ | ✅ | ✅ | ✅ | ❌ | ❌ | Table 2: **R** packages: Supported formats. ## Citation

Hernangómez D (2026). resmush: Optimize and Compress Image Files with reSmush.it. doi:10.32614/CRAN.package.resmush, https://dieghernan.github.io/resmush/.

A BibTeX entry for LaTeX users is @Manual{R-resmush, title = {{resmush}: Optimize and Compress Image Files with {reSmush.it}}, doi = {10.32614/CRAN.package.resmush}, author = {Diego Hernangómez}, year = {2026}, version = {0.2.2.9000}, url = {https://dieghernan.github.io/resmush/}, abstract = {Compress local and online images using the reSmush.it API service .}, } ## References

Xie, Yihui. 2024. *xfun: Supporting Functions for Packages Maintained by Yihui Xie*. .