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Test scope & comparison notes
These are recorded facts, not a unified ranking. Tested tiers and scope are not consistently recorded. Read pricing with its date and timing with its conditions. Privacy observations reflect visible flows and statements, not a security audit.
Cross-task capability coverage across selected products
Each product is scored independently per task edge; switch tasks below while keeping shared products selected| Task edge | Optimizilla | aconvert.com | Switch / compare |
|---|---|---|---|
| Image compression | 88/100 2048 × 2048 · PNG | 86/100 2048 × 2048 · PNG | Active task |
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Browse this task →| Criterion | Optimizilla (ImageCompressor.com) Image compression 88/100 Seven-aspect task score Free login-free on-device processing offers color controls and about 58% PNG reduction; download-like and fullscreen ads create misclick risk. Tested export 2048 × 2048 · PNG Historical test · 2026-10-18 | Aconvert Image compression 86/100 Seven-aspect task score 100% free with no login, reducing the 4.14 MB anchor by 56.5% to 1.80 MB at PSNR 36.1 dB with full-resolution unwatermarked output. Tested export 2048 × 2048 · PNG Historical test · 2026-11-01 |
|---|---|---|
| Pricing & rules | ||
| Pricing plans | ImageCompressor.com in-browser online image compressor · 2026-10-21 Plan · source date Monthly / one-time Annual bill / period Quota & limits Free Browser Compressor2026-10-21 ↗ Free Free Free Free without login; local browser processing for JPEG/PNG/WebP/GIF/SVG with batch compression and per-image quality tuning. 1 plan / billing-period records, all listed; — means that period is not recorded. The official page states that this free online tool runs entirely in the browser with no server uploads required, supporting batch JPEG, PNG, WebP, GIF, and SVG compression with per-image quality tuning, supported by display ads. Cancellation, sources & verification recordAd-supported free tool with no accounts or subscription charges. ImageCompressor.com official page and instructions ↗ · 2026-10-21 Capture 1 ↗ | Aconvert 100% free file conversion and compression service · 2026-11-01 Plan · source date Monthly / one-time Annual bill / period Quota & limits Free2026-11-01 ↗ Free Free Free 100% free without login, 40MB per file, up to 10 files per batch Full access to multi-format conversion and compression across documents, media, eBooks, and archives；40MB per-file limit, 10 files per batch, display ads present；Permanently free, no renewal；Perpetual access 1 plan / billing-period records, all listed; — means that period is not recorded. All conversion and compression features are 100% free with ad and voluntary donation support; 40MB per-file limit (up to 10 files per batch) with zero paid plans or paywalls. Cancellation, sources & verification recordCancellation and refund terms unverified Aconvert Official Homepage ↗ · 2026-11-01 Capture 1 ↗ Aconvert About and Free Model ↗ · 2026-11-01 Capture 1 ↗ |
| Free & trial allowance on the test date | Supports multi-file batch drag-and-drop and per-image palette color tuning (2–256 colors) with no daily cap | Completely free, 40MB per file limit, up to 10 files per batch |
| Cancellation & refunds | Ad-supported free tool with no accounts or subscription charges. | Not verified |
| Disclosure of costs & limits | All features and sliders are unlocked upfront with zero hidden paywalls | Compression parameters and instructions clearly disclosed on page |
| Task quality | ||
| Measured fixture results | File reduction: 57.64% · Output size: 1752.7 KB | File reduction: 56.5% · Output size: 1800.1 KB |
| Fixture findings | Offers before/after preview and colour adjustment; distinguish nearby ad buttons from the real download. | Over 50% size reduction while preserving 2048px resolution and transparency; solid quality and easy to use. |
| Original historical observation | Optimizilla (imagecompressor.com) shines with its interactive Before/After comparison canvas and 'Colors: 224' fine-tuning slider, shrinking our 4.14 MB anchor by 57.64% to 1.75 MB at PSNR=38.98 dB; however, users must watch out for two green 'DOWNLOAD EXTENSION' fake download ad banners directly above and below the workspace (01_landing.png, 02_workspace.png). | Aconvert processes compression on cloud servers, reducing the 4.14 MB anchor by 56.5% to 1.80 MB under default Lossy 80 while maintaining SSIM 0.9966 and preserving micro-textures. |
| Suitable uses · historical assessment | Users who want to manually fine-tune PNG palette color counts (2–256 colors) with a live Before/After preview—provided they avoid the fake 'DOWNLOAD EXTENSION' ad banners | Users and webmasters needing fast free image compression while preserving transparency and 2048px original resolution |
| Result & output evidence | ||
| Delivery capabilities | ||
| Recorded export specifications | 2048 × 2048 · PNG · No watermark in test | 2048 × 2048 · PNG · No watermark in test |
| Historical specification note · not an official maximum | 2048×2048 (no-login native-resolution watermark-free PNG direct export) | 2048 x 2048 (Full-resolution unwatermarked PNG) |
| Watermark observation | Watermark-free | No watermark |
| Batch & API | Supports multi-image batch compression in browser; no developer API | Supports up to 10 files concurrent upload with multi-format conversion |
| Recorded free-tier dimensions | 2048 × 2048 | 2048 × 2048 |
| Attached file dimensions | 2048 × 2048 · PNG | 2048 × 2048 · PNG |
| Speed & reliability | ||
| Timing observation | Recorded local processing time: 11.88s · End-to-end reference: 11.88s | Network-observed server wait: 11.2s · End-to-end reference: 14.7s |
| Date & fixture | 2026-10-18 · anchor_compress_v1 · US-West (California, AS2914) | 2026-11-01 · anchor_compress_v1 · US-West (California, AS2914) |
| Repeated tests & reliability | No standardized repetition count, success rate or variability range is recorded. | No standardized repetition count, success rate or variability range is recorded. |
| Interaction experience | ||
| Account requirements | No login in this test | No login in this test |
| Sign-in methods | No login required (no account system on the site) | All platform features accessible directly without registration or login |
| Manual adjustment | Not verified | Not verified |
| Interaction observations | While there are no sign-up walls, the workspace is flanked top and bottom by deceptive green 'DOWNLOAD EXTENSION / Click "Download" -> Add Trusted Spot Extension' ad banners, and a full-screen Google AdSense overlay (#aswift_3) intercepted the initial COMPRESS click (01_landing.png, 02_workspace.png). | Not verified |
| Background & reputation | ||
| Service lifecycle notice | Not verified | Not verified |
| Operator | Optimizilla / ImageCompressor.com | Aconvert Project (PDFConvertOnline.com) |
| Recorded origin | Independent European Web Utility (Launched 2014) | United States |
| Domain history record | 2014–Present (12-year image compression benchmark) | Development team active since 2000 |
| Background & reputation assessment | Operating since 2014 under the Optimizilla brand, ranking among the highest-traffic search destinations for online image compression. | Not verified |
| External reputation record | Not verified | Not verified |
| Engineering & privacy | ||
| Processing location | On-device processing | Uploaded for cloud processing |
| Third-party tracking record | Not verified | Google AdSense · Google Analytics |
| Engineering & privacy assessment | Modernized architecture runs 100% local in-browser WebAssembly palette quantization ('All processing happens in your browser'), so user photos are never uploaded to a remote server. | Not verified |
| Retention statement | This flow runs locally; post-close deletion not independently verified | Claims deletion within 2 hours; deletion not independently verified |
| Evaluation basis | ||
| Pricing transparency | 32 / 35 100% free across the entire site with zero paywalls or subscription prompts; uploading the 4.14 MB (2048×2048) anchor image and clicking COMPRESS immediately unlocks the SAVE ALL export button without login (01_landing.png, 02_workspace.png, 03_download.png). | |
| Interaction restraint | 20 / 30 While there are no sign-up walls, the workspace is flanked top and bottom by deceptive green 'DOWNLOAD EXTENSION / Click "Download" -> Add Trusted Spot Extension' ad banners, and a full-screen Google AdSense overlay (#aswift_3) intercepted the initial COMPRESS click (01_landing.png, 02_workspace.png). | |
| Background & reputation | 18 / 20 Operating since 2014 under the Optimizilla brand, ranking among the highest-traffic search destinations for online image compression. | |
| Engineering & privacy | 14.5 / 15 Modernized architecture runs 100% local in-browser WebAssembly palette quantization ('All processing happens in your browser'), so user photos are never uploaded to a remote server. | |
| Task quality | 59.5 / 65 Default 224-color PNG palette quantization shrinks the 4,137.9 KB anchor down to 1,752.7 KB (-57.64%, 2.36× ratio) at PSNR = 38.98 dB and SSIM = 0.9983, with an interactive 2–256 Colors slider and live Before/After canvas preview (59.5/65) | 56 / 65 Size Reduction: -56.5% (4137.9 KB → 1800.1 KB, 2.3× ratio) · PSNR: 36.1 dB · SSIM: 0.9966 |
| Deliverable specifications | 20 / 20 Preserves 100% of the 2048×2048 pixel dimensions and native PNG format without watermarks or login requirements (20.0/20) | 20 / 20 Clean unwatermarked export (8/8); Export spec: 2048 x 2048 (Full-resolution unwatermarked PNG) |
| Processing speed | 10.5 / 15 Local browser 224-color palette quantization on the 2048×2048 PNG takes ~11.88s and requires clicking COMPRESS followed by SAVE ALL (10.5/15) | 8.5 / 15 Network-observed server wait: 11.2s (API mode: cloud_server; network upload 3.5s / end-to-end 14.7s shown for reference only, never penalized) |
