resmush is a R package that allows users to optimize and compress images using reSmush.it. reSmush.it is a free API that provides image optimization and has been implemented in WordPress and many other tools.
Some of the features of reSmush.it include:
png, jpg/jpeg,
gif, bmp, tiff.Install resmush from CRAN with:
install.packages("resmush")Check the docs of the developing version in https://dieghernan.github.io/resmush/dev/.
You can install the development version of resmush from GitHub with:
# install.packages("pak")
pak::pak("dieghernan/resmush")Alternatively, install resmush using the r-universe:
# Install resmush in R:
install.packages(
"resmush",
repos = c(
"https://dieghernan.r-universe.dev",
"https://cloud.r-project.org"
)
)Compressing an online jpg image:
library(resmush)
url <- "https://dieghernan.github.io/resmush/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 178.7 Kb
#> ✔ Success for 1 url: Size now is 45 Kb (was 178.7 Kb). Saved 133.7 Kb (74.82%).
#> See result in directory 'man/figures'.
(a)
(b)
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.
# 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 178.7 Kb
#> ✔ Success for 1 url: Size now is 2.2 Kb (was 178.7 Kb). Saved 176.4 Kb (98.74%).
#> See result in directory 'man/figures'.
qlty = 3).
All the functions return (invisibly) a dataset summarizing the process. The following example shows how this works when compressing a local file:
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
#> <chr> <chr> <chr> <chr> <dbl> <dbl>
#> 1 239.9 Kb 70.7 Kb 70.54% OK 245618 72356Several other R packages also provide image optimization tools:
xfun::tinify(): Similar to resmush_file()
but uses TinyPNG and
requires an API key.xfun::optipng(): Compresses local files using
OptiPNG, which must be installed locally.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 | |
|---|---|---|---|---|---|---|---|
xfun::tinify() |
✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ |
xfun::optipng() |
✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| tinieR | ✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ |
| optout | ✅ | ✅ | ❌ | ❌ | ❌ | ❌ | ✅ |
| resmush | ✅ | ✅ | ✅ | ✅ | ✅ | ❌ | ❌ |
Table 2: R packages: Supported formats.
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 = {1.0.0},
url = {https://dieghernan.github.io/resmush/},
abstract = {Compress local and online images using the reSmush.it API service <https://resmush.it/>.},
}