If your website feels slow, oversized images are usually the first culprit. A single unoptimized JPEG or PNG can add a full second to a page load, and Google's Core Web Vitals score you on exactly that. The good news is you don't need a paid subscription to fix it — some of the best image tools available are free, and a few of them never even upload your file to a server. Here are five worth knowing, including two brand-new local-first options and the established names developers have relied on for years.
1. Pictiur — convert, resize and compress in one pass, 100% locally
Pictiur is a free, open-source (MIT) browser tool that runs entirely on WebAssembly — meaning your image never leaves your device. It bundles conversion, resizing and compression into a single pass instead of making you chain three separate tools together, and it supports a genuinely wide format list including AVIF, JPEG XL and HEIC/HEIF input. It even installs as an offline-capable PWA, and there's a Docker image if you'd rather self-host it behind your own login.
Pricing: Free and open source, self-hostable at no cost.
Forces: Fully client-side (nothing uploaded), combines three steps into one, wide modern-format support, self-hostable.
Limites: Very new — zero GitHub stars and no independent reviews yet, solo-developer project so long-term maintenance is unproven, no documented batch processing.
Pick Pictiur if: you want the strongest privacy guarantee (nothing ever touches a server) and you're comfortable being an early adopter of a small project.
2. Hikaru Labs — hit an exact target file size
Hikaru Labs is a browser-based image toolbox covering conversion, compression, resizing, batch processing and watermarking. Its standout feature is compressing an image down to an exact target file size — useful when a form or CMS enforces a hard upload limit — instead of the usual trial-and-error with a quality slider.
Pricing: Free "Guest" tier; paid tiers for higher limits and team features (billed in Indian rupees, current prices not independently confirmed).
Forces: Exact-file-size compression mode, several tools (convert/compress/resize/batch/watermark) in one place, no full account required for basic use.
Limites: Still requires a Guest sign-in, which undercuts the "fully local" pitch; pricing isn't independently verifiable; on-page traction claims read more like marketing than fact.
Pick Hikaru Labs if: you specifically need to hit a byte-size limit rather than just "make it smaller."
3. Squoosh — Google's classic, still the developer default
Squoosh has been the go-to free compressor for developers, webmasters and photographers for years, and it's still genuinely good. It runs in the browser, is completely free with no account, and its real-time before/after comparison slider makes it easy to see exactly how much quality you're trading for file size.
Pricing: Free.
Forces: Real-time comparison view, efficient compression, zero cost, no sign-up.
Limites: No auto-save, and the interface is fairly bare-bones — one image at a time, no batch mode.
Pick Squoosh if: you want the most battle-tested, no-frills option and don't need batch processing.
4. TinyPNG — the simplest one-click compressor
TinyPNG is the tool most people reach for first: drag in a PNG, WebP or JPEG, and it comes back smaller with almost no visible quality loss. It's freemium — the free tier caps how many images you can compress before it asks you to upgrade to the Pro plan (from $25/month).
Pricing: Free tier with a compression cap; Pro from $25/month.
Forces: Very simple interface, efficient compression, supports multiple formats.
Limites: Free tier limits the number of images; compression speed varies with file size.
Pick TinyPNG if: you want the fastest possible workflow for occasional, one-off compressions.
5. CloudConvert — when you need actual format conversion, not just compression
CloudConvert is less about squeezing bytes and more about converting between the 200+ formats it supports — image, document, audio and video alike. It's the tool to reach for when TinyPNG or Squoosh can technically compress a file but you actually need to turn a HEIC into a JPEG, or a batch of files into a specific format for a pipeline.
Pricing: Free up to 25 conversion minutes/day; paid plans from €8/month.
Forces: Over 200 supported formats, accessible from anywhere, fast conversion.
Limites: Free tier is time-capped, not count-capped, which can run out fast on large files; files are uploaded to their servers, so it's not the choice for sensitive images.
Pick CloudConvert if: your actual problem is format conversion at scale, not just shrinking file size.
How they compare
| Tool | Runs locally? | Best for | Price |
|---|---|---|---|
| Pictiur | Yes (WASM) | Privacy-first all-in-one | Free, open source |
| Hikaru Labs | Partial (guest login) | Exact target file size | Free tier + paid |
| Squoosh | Yes | Quick manual compression | Free |
| TinyPNG | No (cloud) | One-click simplicity | Free tier, Pro $25/mo |
| CloudConvert | No (cloud) | Format conversion at scale | Free 25min/day, from €8/mo |
None of these require a subscription to get real value. If keeping images off someone else's server matters to you, Pictiur and Squoosh are the two that actually deliver on that — everything else, however convenient, is sending your files to a cloud service somewhere.