Correction, 2026-10-02: this page did not say that the 8frame upscale tool starts on Topaz, which always enlarges 4x and is priced by the size of the result (11 credits per started 24 MP block of output, up to 281), or that Clarity always enlarges 2x and is diffusion-based, so it can redraw fine detail. It described a "generate, upscale, export formats" chain as a reusable workflow, but 8frame has no export-preset node. Two statements were presented as fact without measurement: that many free upscaler sites wrap the same open models with a meter, and that an upscale pass removes softness from AI images. They are now advice. We re-checked every free-tier limit on the tool's own page today.
Correction, 2026-09-30: we credited Upscayl's desktop app with face restoration (only its paid Cloud has face enhancement), called imgmend watermark-free (its free downloads are watermarked), and described every browser tool as a few images a day (Bigjpg is 20 a month; waifu2x states size limits instead). Fixed from each tool's own pages.
The best free AI upscaler in 2026 is Upscayl: a free and open source desktop app (AGPL-3.0) for Windows, macOS and Linux that upscales on your own graphics card, so your images stay on your machine. The browser tools are for the moment you cannot install anything, and each states its own limit: Bigjpg 20 images a month, imgmend 3 a day at 2x with a watermark, waifu2x a size cap. Disclosure: 8frame is our product, upscaling on it is paid (from 6 credits an image), and the honest framing is that free covers most casual upscaling jobs, while paid earns its cost on volume inside a workflow.
TL;DR
- Best free, full stop: Upscayl. Open source, runs on your own GPU, bundled 4x models. Face enhancement is only in its paid Cloud version
- Best without installing anything: waifu2x (5 MB, up to 1,500 x 1,500 px for upscaling, no daily cap stated), Bigjpg (20 images a month free, up to 4x), imgmend (3 a day, 2x only, watermarked on free)
- The catch pattern: browser tools meter by day, by month or by file size; a local tool costs you compute time instead
- Privacy note: local processing means client work never touches a third-party server, which for agencies is the whole decision
- Where paid starts to win: volume inside a workflow. Video upscaling is a desktop-tool job: the tools here are image upscalers, and 8frame does not upscale video either
The picks
1. Upscayl
Free, open source (AGPL-3.0) and running on your own graphics card, which settles cost and privacy: the images are processed on your device. It needs a Vulkan-compatible GPU, and the install asks for no sign-in. The bundled models (Upscayl Standard, Lite, High Fidelity and Digital Art among them) are all 4x; per the app itself, anything above 4x except its 16x Double Upscayl only resizes the image. Three bundled models (Remacri, Ultramix, Ultrasharp) are labelled non-commercial, so pick another for client work. There is no face restoration in the desktop app; the paid Upscayl Cloud lists face enhancement as an extra. The cost is compute time on your own machine.
If you upscale occasionally and can install software, stop reading here. The rest of the list is for constraints Upscayl does not fit.
2. The browser tier: waifu2x, Bigjpg, imgmend
For the machine you cannot install on. Each states a different limit, checked on their own pages on 2026-10-02:
- waifu2x (now at waifu2x.net) is built for anime-style art and "supports photo". Limits: 5 MB per file and 1,500 x 1,500 px for upscaling, at 1.6x, 2x or 4x. No daily cap and no login on the page. An experimental in-browser version runs on your own device.
- Bigjpg: free plan of 20 images a month at up to 4x and 5 MB, no login required. Paid plans start at $6 for two months and 500 images.
- imgmend: 2x upscaling "is completely free", with "no account, 3 images per day, with a small watermark on downloads"; 4x and watermark-free downloads cost a one-time $9.90.
Fine for one-off jobs; the caps make them a workflow dead end.
What to avoid
A watermarked upscale for anything client-facing (imgmend's free tier watermarks its downloads), and a subscription for what Upscayl does free. Before you pay for a browser upscaler, check whether it does anything that Upscayl's free bundled models do not.
Where free stops
Two places, and they are specific.
Volume inside a workflow. Upscaling one hero image is a free-tool job. Upscaling every frame-grab, variant, and format version of a campaign means the upscaler needs to sit where the images are generated. 8frame has three image upscalers on the same canvas as the generation. The upscale tool starts on Topaz, a fixed 4x enlargement at 11 credits per started 24 MP block of output, up to 281, so its price follows the size of the result. Clarity is 13 credits flat and always enlarges 2x; it is diffusion-based, so it redraws detail, and text and faces are worth checking. BRIA Increase Resolution is 6 flat, 2x or 4x up to 8192 x 8192. The two flat options are about $0.06 and $0.13 at pack rate, and the chain (generate, then upscale) becomes a reusable workflow instead of a download-upload loop per image. Topaz vs Clarity covers which to pick.
Video is a different problem, and we do not solve it. The free tools above are image upscalers, and 8frame does not upscale video either: Topaz, Clarity and BRIA on the canvas work on stills only. Video upscaling belongs in a dedicated desktop tool after export. The practical workaround is to avoid needing it: generate at the resolution you intend to deliver, since Wan 3.0 (up to 1080p) and Seedance (up to 720p) both expose a resolution setting. There is no video upscaler on 8frame to rescue a 480p clip later, so pick the delivery resolution up front.
The pattern that uses both correctly: free local upscaling for one-off stills and personal work, paid in-workflow upscaling where volume makes the round-trip the actual cost, and for video, generation at the resolution you deliver.
FAQ
What is the best free AI upscaler without a watermark? Upscayl, a free and open source desktop app that runs on your own GPU. In the browser, the waifu2x and Bigjpg pages do not mention a watermark on free output; imgmend's free tier watermarks its downloads.
Is there a free unlimited AI upscaler online? Not with every feature. waifu2x's site states size limits rather than a daily cap (5 MB and 1,500 x 1,500 px for upscaling), Bigjpg gives 20 images a month and imgmend 3 a day. For volume without a meter, run Upscayl on your own machine.
Does upscaling improve AI-generated images? It can, and it is cheap to test. Generation resolution is a cost lever, so generating at a lower setting and upscaling only the keepers can cost less than generating everything large. Compare the upscale with the original at full size: a diffusion-based upscaler such as Clarity redraws detail, so check text and faces before you keep it.
Does 8frame upscale video? No. Topaz, Clarity and BRIA Increase Resolution on 8frame work on still images only; there is no video upscaler.
Sources
- Upscayl: github.com/upscayl/upscayl (licence, supported systems, GPU requirement, bundled models and scale behaviour in the app's own strings), upscayl.org (Cloud features, including face enhancement) and upscayl.org/pricing, checked 2026-10-02
- waifu2x: waifu2x.net and the experimental in-browser version at unlimited.waifu2x.net, checked 2026-10-02
- Bigjpg: bigjpg.com, checked 2026-10-02
- imgmend: imgmend.com/upscale-image, checked 2026-10-02
- 8frame upscalers (Topaz as the starting option, fixed 4x, 11 per started 24 MP block of output, up to 281; Clarity 13, always 2x, diffusion-based; BRIA Increase Resolution 6, 2x or 4x up to 8192 x 8192; no video upscaler; no export-preset node) and Wan 3.0 and Seedance resolutions: 8frame tool registry and content fact sheet, read 2026-10-02
Related
- Topaz vs Clarity: the three 8frame upscalers, what each costs and which to pick
- Best free AI video enhancers: why generating at delivery resolution beats repairing
- Best free AI image editors
- Best free AI background removers
- Best free AI thumbnail makers
Free covers the one-off; the workflow is where paid earns it.
Try it without signing up: the 8frame canvas opens on a real board. The canvas is free and unlimited; generation is paid from $19/month.