Guides · 82 articles
Image Optimization Guides
In-depth articles about modern image formats, compression techniques, and best practices for web performance.
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AI Image Compression and Conversion: Describe the Result, Skip the Settings
Describe the result in plain English and let Mochify pick the format, quality and size. How natural-language image compression works, from a browser prompt to a fully agentic pipeline.
On-Device AI Agents: Image and PDF Optimization for Local Workflows
From NVIDIA DGX Spark to Apple Silicon, local AI agents are real in 2026. What that means for handling images and PDFs inside MCP agent pipelines - and why a local model doesn't mean local data.
How the Mochify MCP Server Works: Hosted vs Local, with Worked Examples
The hosted and local MCP surfaces compared - architecture, token costs, retention behavior, and four worked examples covering URL input, uploaded images, Claude Desktop file work, and build pipelines.
How to Blur Faces or a License Plate in a Photo (Ask Your AI Assistant)
Ask your AI assistant to hide a license plate, faces or an address: it finds the area, Mochify redacts it and strips the metadata. Why fill beats blur.
Can ChatGPT Compress a Photo? We Measured What Comes Back
One 24 MP iPhone photo, five AI chatbots, every returned file measured. The compression happened at upload, before any model saw it. What comes back.
How Do I Give a CSS Background Image a WebP or AVIF Fallback?
Use image-set() with type() for the AVIF and WebP, with a plain url() JPEG line before it. Baseline since September 2023; what older Safari gets.
Convert a Website's Images to WebP and AVIF, and Keep Them That Way
Convert every image on your site to WebP and AVIF, then keep new ones converted: one command for the batch, a script for new files, serving, and WordPress.
The HTML <picture> Tag (Picture Element): Format Fallbacks, Art Direction and the 2026 Source Order
The HTML picture tag, explained: AVIF, WebP and JPEG fallbacks in the right order, art direction, dark mode, and the four rules that make it render.
How to Compress a PDF on Mac Without Losing Quality
What Preview's Reduce File Size really does (JPEG 0.7, 144 dpi on macOS 27), a custom filter for print, the iOS 27 route, and a one-prompt alternative.
JPEG XL Is in Chrome: What Changes for Your Images, and What Does Not Yet
Chrome 155 decodes JPEG XL by default from October 6, 2026; Firefox 158 follows on October 13. Browser table, caveats, and what to do by stack.
Lossless Image Formats: Which One to Use, and When Lossless Is the Wrong Choice
PNG, WebP, JPEG XL and AVIF tested lossless on six image types: which wins for screenshots, logos and photos, and when lossless is the wrong call.
How to Reduce Photo File Size on iPhone: The Fast Way and the Free Built-In Way
Reduce photo file size on iPhone, free: compress a photo to 1MB in seconds in Safari, or use Preview's Export slider on iOS 26 and later. No app needed.
Save Image as Type Is Gone: How to Replace It Safely
Save Image as Type was removed as malware. How to check your browser, vet a replacement, and save any image as JPG, PNG, AVIF, JPEG XL or PDF.
How to Batch Crop Photos to Square
Every batch crop tool applies one rectangle to every photo. How batch cropping to square actually works on Windows, Mac, iPhone and the command line.
How to Save a WebP as JPG in Chrome
Chrome did not convert your image and renaming the file does nothing. The four routes that actually re-encode a WebP as JPG, one of them built into Chrome.
Do WebP and AVIF Support Transparency?
Yes, both carry a full alpha channel. Why a transparent cut-out comes back black or white, the five causes, and how to check a file before blaming the format.
Does JPEG Support HDR?
Yes: a JPEG can carry HDR as a gain map (Ultra HDR, Adaptive HDR, ISO 21496-1) and opens everywhere. Why most "JPG to HDR" converters give you the wrong file.
How to Make Any Photo Ultra HDR (Google Photos, Samsung, iPhone, Lightroom, or Online)
Convert any photo to Ultra HDR on Google Photos, Samsung, iPhone, Lightroom or online: what conversion really does, exact steps, and where the result displays.
Why Did My Upload Fail? Every Mochify Error, Explained
Every upload and conversion error Mochify shows, what caused it, what we already did about it, and the one thing to try next. From the engineers who built it.
JPEG XL vs PNG for Screenshots: Half the Size, Same Pixels
A measured comparison: one macOS screenshot at 1.84 MiB as PNG and 0.99 MiB as lossless JPEG XL. Why screenshots compress so well, what lossless really guarantees, and when to stay on PNG.
Bring Your Own Bucket: Send Processed Images Straight to Your Own S3 or R2
Send every processed image straight into your own S3, R2, or S3-compatible bucket. Paid plans, write-only, one-object pre-signed URLs, zero retention.
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