Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteUse the screenshot provider’s documented User-Agent option, with the exact field name and encoding that its endpoint expects. For example, Cloudflare Browser Run uses userAgent in a JSON body, while ScreenshotOne documents user_agent as a request parameter. A custom string controls one request signal; it does not set the viewport or guarantee access past bot protection.
Set the value using your provider’s syntax
First identify whether the screenshot endpoint accepts a JSON body, query parameters, or another request format. Then use its dedicated User-Agent setting where available. Names are not standardized across providers: casing and transport format matter.
As an Amazon Associate I earn from qualifying purchases.
Cloudflare Browser Run
Cloudflare Browser Run accepts userAgent as a top-level JSON parameter. The following shows the field shape only; it is not a complete request or a tested example:
{
"url": "https://example.com/",
"userAgent": "Mozilla/5.0 (compatible; ExampleBot/1.0)"
}Choose a value that accurately describes the software condition you are testing. Cloudflare says setting userAgent does not bypass bot protection; requests can still be identified as bot traffic through headers that cannot be changed. See the Cloudflare Browser Run screenshot endpoint documentation.
#1 Best Overall
- 【WIRELESS MOBILE MINI TRAVEL ROUTER】 Convert a public network (wired or wireless) to a private Wi-Fi for secure surfing. Tethering. Powered by any laptop USB, power banks or 5V/2A DC adapters (sold separately). 39g (1.41 Oz) only, portable and pocket friendly. 2.4GHz ONLY
- 【OPEN SOURCE & PROGRAMMABLE】 OpenWrt pre-installed, USB disk extendable.
- 【LARGER STORAGE & EXTENDABILITY】 128MB RAM, 16MB Flash ROM, dual Ethernet ports, UART and GPIOs available for hardware DIY.
- 【OPENVPN CLIENT】 OpenVPN client pre-installed, compatible with 30+ VPN service providers.
- 【PACKAGE CONTENTS】 GL-MT300N-V2 (Mango) mini router (2-year Warranty), USB cable, Ethernet cable, User Manual. Please update to the latest firmware.
Cloudflare Browser Rendering API
The Browser Rendering screenshot schema lists optional userAgent and a separate setExtraHTTPHeaders option. It also provides viewport configuration, so do not treat a User-Agent override as a substitute for viewport settings. Check the Cloudflare Browser Rendering screenshot API reference for the endpoint’s request schema.
ScreenshotOne
ScreenshotOne documents the user_agent request parameter; its example uses user_agent=screenshoter. Its documented default is the latest version of the browser used by Puppeteer. The provider warns that changing the value may affect stealth-mode capabilities. It also documents that viewport_device overrides user_agent, so remove or change that preset if your custom value is not taking effect. Check the current ScreenshotOne options documentation and its device and viewport option precedence documentation.
Rank #2
- 【Advanced Home Data & Media Hub】For advanced home users who need phone backup, file storage, and centralized data management. Centralize family photos, 4K videos, movies, computer backups, and personal files in one place while running multiple apps for home entertainment and everyday data management. Suitable for households with growing digital libraries and multiple NAS use cases.
- 【Built for Creators, Media Servers & Advanced Apps】Powered by the Intel N100 Quad-Core CPU, 8GB DDR5 RAM, 2.5GbE networking, and dual M.2 NVMe slots, DXP2800 handles large files and heavier workloads with ease. Run Docker, virtual machines, and media server applications compatible with Plex—ideal for content creators, tech enthusiasts, and advanced home users managing 4K videos, RAW photos, personal media libraries, and multiple NAS apps.
- 【Up to 80TB for Growing Digital Libraries】 Supports up to 80TB of storage using two HDD bays and two M.2 NVMe SSD slots for family photos, movies, RAW photos, 4K videos, work files, and device backups. AI photo management supports recognition of people, objects, scenes, and locations, album organization, and duplicate photo detection. HDDs and SSDs are not included.
- 【AI-powered Home Surveillance】Turn DXP2800 into a centralized home surveillance hub by connecting compatible network cameras and storing recordings locally on your NAS. AI-powered features include Face Recognition, People Detection, and Pet Detection, helping advanced home users review important events more efficiently while managing home surveillance and personal data in one place.
- 【One data Center Across Your Devices】Keep files from desktops, laptops, phones, tablets, and other devices together instead of scattered across cloud accounts and external drives. Access, back up, organize, and share data across Windows, macOS, Android, iOS, web browsers, and compatible smart TVs—ideal for creators and advanced home users working across multiple devices.
Other providers and local capture
Provider syntax varies. Screenshots.Dev, ScreenshotRun, Screenshot Machine, and ScreenshotCenter document User-Agent options, but verify each service’s current field name, casing, and request encoding before adapting an example. Their documentation includes Screenshots.Dev API docs, ScreenshotRun device docs, and the Screenshot Machine API.
For local rather than hosted capture, shot-scraper provides a --user-agent TEXT option and supports Chromium, Firefox, WebKit, Chrome, and Chrome Beta. See the shot-scraper documentation.
Rank #3
- One Place for All Your Data - Consolidate scattered files from multiple computers, phones and external drives into one accessible hub with 100% ownership
- Professional File Collaboration - Share projects with clients, sync documents across teams and maintain version control without Dropbox fees
- Automated Backup Protection - Set-and-forget backups for Macs, PCs and mobile devices to multiple destinations including cloud and external drives
- DIY Surveillance System - Transform IP cameras into a professional monitoring solution with motion alerts, recording schedules and remote viewing
- 2-Year Warranty - Reliable hardware backed by Synology's expert customer support team and ongoing software updates
Keep User-Agent separate from device emulation
The HTTP User-Agent header is a string that can identify aspects of the requesting application, operating system, vendor, or version. It is not the viewport size, device pixel ratio, touch support, or browser engine. A string that resembles a mobile browser does not by itself make the screenshot a faithful mobile-device rendering. MDN also notes that User-Agent information can contribute to fingerprinting; browsers limit information exposed through this header and related APIs. See MDN’s User-Agent header reference.
Configure these independently when your test requires them:
Rank #4
- Unlimited bandwidth, unlimited data.
- Super-fast VPN and one tap connect.
- Free worldwide multiple servers.
- Works with all type of data carries. (Wi-Fi, 4G, LTE, 3G).
- No registration, sign up needed.
- User-Agent: the request’s declared software identity.
- Viewport: the page’s CSS layout dimensions.
- Device scale: the relationship between CSS pixels and output pixels.
- Mobile or touch behavior: separate emulation controls, if the provider offers them.
- Extra request headers: separate from the User-Agent option where the provider documents them.
Cloudflare documents viewport configuration separately from userAgent; ScreenshotOne documents viewport and device-scale settings. A device preset may impose precedence rules, so inspect the provider’s schema rather than assuming all options combine.
Verify the request and interpret the result
- Confirm the endpoint and request method, then copy the User-Agent option exactly as documented, including capitalization and encoding.
- Set viewport, device, and other emulation settings separately. Check whether a preset overrides the custom string.
- Capture a page that displays the received User-Agent, or inspect the page content returned by your test target, to verify that the value reached the document.
- Interpret the screenshot as the result of that request, not a guarantee that the server selected a specific variant or that the page loaded successfully.
ScreenshotOne’s documentation points to a User-Agent checking page in its example, but the available documentation does not establish independent test results for any provider. A custom value can help reproduce user-agent-dependent responses; it cannot promise a particular rendering or successful access.
Best Value
- Complete Phone & Computer Backup - Automatically protect photos, documents and videos from iPhone android, Mac and Windows to one secure location
- Your Private File Cloud - Access files from anywhere and share large projects with family or clients without relying on expensive cloud subscriptions
- Smart Home Security Hub - Monitor your home 24/7 with AI-powered surveillance that detects people, vehicles and sends instant alerts
- 100% Data Ownership - Keep full control of your personal data with multi-platform access and no monthly subscription fees
- 2-Year Warranty - Reliable hardware backed by Synology's expert customer support team and ongoing software updates
Common problems and fixes
- The override appears ignored: check spelling, casing, and whether the value is in the right part of the request. For ScreenshotOne, check whether
viewport_deviceis overridinguser_agent. - The page still shows a bot check or refuses the request: a User-Agent string is not an access-control workaround. Cloudflare explicitly says Browser Run requests remain identifiable as bot traffic through non-configurable headers.
- The screenshot has desktop layout despite a mobile-looking value: set the viewport and any documented mobile, touch, or device-preset options separately.
- Changing the value alters provider behavior: restore the documented default and compare. ScreenshotOne warns that overriding its default may affect stealth-mode capabilities.
- Extra headers do not change User-Agent: use the provider’s dedicated setting when documented; general extra-header handling may be distinct or have special rules.
Or skip the browser setup
ScreenshotNeo accepts a User-Agent option along with custom headers, cookies, and other capture settings. Its parameter names also work with names used by other screenshot APIs, which can make switching easier. A basic request looks like this:
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpSee the ScreenshotNeo API documentation for the User-Agent parameter and other options. ScreenshotNeo removes cookie and consent banners, newsletter popups, and chat widgets before capture; each step can be turned off. Bot checks, blank pages, failed loads, timeouts, and cache hits are not billed, and the response indicates the page verdict and billing status. Its MCP server gives AI agents tools to take screenshots, get page information, and capture PDFs. The free plan includes 1,000 screenshots a month with no card; paid plans start at $5 for 3,000. Sign up for ScreenshotNeo’s free plan.
Frequently Asked Questions
Does a custom User-Agent make a screenshot API look like a real phone?
No. It changes the User-Agent value only; viewport, device scale, and mobile or touch emulation are separate settings.
Can changing User-Agent get past a CAPTCHA or bot check?
No. A custom string does not guarantee access, and Cloudflare says its Browser Run requests remain identifiable as bot traffic.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
