Honest, hands-on reviews of image resizer, compressor, and format-conversion tools — grouped by the job you are actually trying to do.
These pages do not exist to rank for generic "best tool" keywords. Each roundup is scoped to a real workflow — bulk resizing, Instagram-ready dimensions, iPhone batch processing — and benchmarks the tools we would actually reach for on a given day.
Pages in this section
We tested seven free image resizers on real iPhone JPEGs, transparent PNGs, and screenshots. Here is which one to pick for each workflow — and which ones quietly upload your file.
Five PNG-focused resizers tested against transparent logos, screenshots, and UI captures. Ranked by which preserves alpha channel, compression quality, and indexed-color output.
Five JPG-focused resizers tested against a 12 MP iPhone photo. Ranked by MozJPEG support, quality-slider precision, chroma subsampling control, and progressive encoding.
Five tools tested for Instagram-specific resizing. Ranked by preset accuracy (1080×1080, 1080×1350, 1080×1920), aspect-ratio safety, and export-quality defaults.
Five bulk resizers tested with a 100-file JPEG batch. Ranked by throughput, batch-size limits, parallel processing, ZIP output, and whether processing stays in the browser.
Five native iPhone resizer apps tested for offline support, Photos integration, batch, and export quality. No web tools, no browser dependencies.
Quick answers
Most "best X" listicles are affiliate-driven or autogenerated. These pages publish the evaluation method up front, test tools on real files, and carry a visible last-updated date. When a tool changes materially, the roundup is rerun.
At least twice a year, and whenever a reviewed tool ships a material change — new pricing, a new feature, or a removed free tier.