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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 | JPEG-Optimizer | aconvert.com | Switch / compare |
|---|---|---|---|
| Image compression | 95/100 2048 × 2048 · PNG | 86/100 2048 × 2048 · PNG | Active task |
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Browse this task →| Criterion | JPEG-Optimizer (Browser-Local PNG/JPEG/GIF Compressor) Image compression 95/100 Seven-aspect task score Free login-free on-device processing supports target sizes, retaining full-size PNG with about 62% reduction in this run; display ads occupy the sidebar. Tested export 2048 × 2048 · PNG Historical test · 2026-10-19 | 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 | JPEG-Optimizer in-browser bulk image compressor and resizer · 2026-10-21 Plan · source date Monthly / one-time Annual bill / period Quota & limits Completely Free Web2026-10-21 ↗ Free Free Free Completely free without login; up to 20 images at once processed locally in the browser for JPEG/PNG/GIF. 1 plan / billing-period records, all listed; — means that period is not recorded. The official page states "Completely Free. 20 images at once." and "Files are NEVER sent to the server, and all processing is handled via your own browser," supporting JPEG/PNG/GIF quality, max KB size, and max dimension settings. Cancellation, sources & verification recordCompletely free in-browser tool with no accounts or paid subscriptions. JPEG-Optimizer official page and privacy notice ↗ · 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 | 100% free with up to 20 images per batch and one-click ZIP download | Completely free, 40MB per file limit, up to 10 files per batch |
| Cancellation & refunds | Completely free in-browser tool with no accounts or paid subscriptions. | Not verified |
| Disclosure of costs & limits | Free batch quota and browser-local privacy guarantee are disclosed upfront above the fold | Compression parameters and instructions clearly disclosed on page |
| Task quality | ||
| Measured fixture results | File reduction: 61.76% · Output size: 1582.4 KB | File reduction: 56.5% · Output size: 1800.1 KB |
| Fixture findings | Local processing reduced this fixture by about 62%; other formats and images need separate tests. | Over 50% size reduction while preserving 2048px resolution and transparency; solid quality and easy to use. |
| Original historical observation | Despite its legacy 'JPEG-Optimizer' name, the tool fully supports client-side PNG, JPEG, and GIF compression. It shrinks our 4.14 MB anchor PNG by 61.76% to 1.55 MB locally in 1.4s with PSNR=39.35 dB and SSIM=0.9984 (02_workspace.png, 03_download.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 | Privacy-conscious users who strictly prohibit cloud uploads and need fast 20-image batch PNG/JPEG compression in the browser | 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 (native resolution watermark-free PNG direct export) | 2048 x 2048 (Full-resolution unwatermarked PNG) |
| Watermark observation | Watermark-free | No watermark |
| Batch & API | Supports 20-image batch local compression and ZIP archive export; no external 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: 1.4s · End-to-end reference: 1.4s | Network-observed server wait: 11.2s · End-to-end reference: 14.7s |
| Date & fixture | 2026-10-19 · 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 site) | All platform features accessible directly without registration or login |
| Manual adjustment | Not verified | Not verified |
| Interaction observations | One-click quality slider, target max KB, and dimension controls without login; exports directly via a browser blob: URL with only standard sidebar display ads. | Not verified |
| Background & reputation | ||
| Service lifecycle notice | Not verified | Not verified |
| Operator | JPEG-Optimizer (jpeg-optimizer.com) | Aconvert Project (PDFConvertOnline.com) |
| Recorded origin | Independent Web Utility | United States |
| Domain history record | 2010–Present (16-year established domain) | Development team active since 2000 |
| Background & reputation assessment | Long-running web image optimization utility (jpeg-optimizer.com) operating since 2010, modernized with a pure client-side browser processing pipeline. | 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 | Explicitly promises and verified via network inspection: 'Privacy: Files are NEVER sent to the server, and all processing is handled via your own browser.' 100% client-side zero-upload execution. | 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 | 33.5 / 35 Clearly states 'Completely Free. 20 images at once.' on the landing page (01_landing.png) with zero paywalls, zero sign-up gates, and zero hidden limits; importing our 4.14 MB anchor PNG immediately generates a free local Download link and ZIP batch archive button (02_workspace.png, 03_download.png). | |
| Interaction restraint | 27.5 / 30 One-click quality slider, target max KB, and dimension controls without login; exports directly via a browser blob: URL with only standard sidebar display ads. | |
| Background & reputation | 18 / 20 Long-running web image optimization utility (jpeg-optimizer.com) operating since 2010, modernized with a pure client-side browser processing pipeline. | |
| Engineering & privacy | 15 / 15 Explicitly promises and verified via network inspection: 'Privacy: Files are NEVER sent to the server, and all processing is handled via your own browser.' 100% client-side zero-upload execution. | |
| Task quality | 61.2 / 65 Preserves native 2048×2048 PNG format at default 80% quality while shrinking 4,137.9 KB down to 1,582.4 KB (61.76% reduction, 2.61× ratio) with PSNR = 39.35 dB and SSIM = 0.9984 (61.2/65) | 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 / 20 100% preserves 2048×2048 pixel dimensions and native PNG format without watermarks or login (20.0/20) | 20 / 20 Clean unwatermarked export (8/8); Export spec: 2048 x 2048 (Full-resolution unwatermarked PNG) |
| Processing speed | 13.8 / 15 100% local browser computation (0s network upload), completing 4.14 MB PNG compression in ~1.4s (13.8/15) | 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) |
