Software Alternatives, Accelerators & Startups

Fiddler VS Postmate Client

Compare Fiddler VS Postmate Client and see what are their differences

Fiddler logo Fiddler

Fiddler is a debugging program for websites.

Postmate Client logo Postmate Client

Privacy-first API client for VS Code โ€” no login, no cloud sync, no telemetry.
  • Fiddler Landing page
    Landing page //
    2023-09-19
  • Postmate Client Postmate Client running inside VS Code โ€” request builder
    Postmate Client running inside VS Code โ€” request builder //
    2026-07-07
  • Postmate Client Compare JSON responses side by side
    Compare JSON responses side by side //
    2026-07-07
  • Postmate Client Collection Runner โ€” run entire suites with one click
    Collection Runner โ€” run entire suites with one click //
    2026-07-07
  • Postmate Client HTML test execution report
    HTML test execution report //
    2026-07-07

Postmate Client is a free, privacy-first API client that runs natively inside VS Code. Test REST, GraphQL, and WebSocket APIs without leaving your editor โ€” no account required, no cloud sync, no telemetry. All requests, environments, and data stay on your machine.

Every feature is included, free โ€” there is no paid tier:

  • REST, GraphQL, and WebSocket requests with variable autocomplete
  • Collections and environments with instant switching
  • Request chaining โ€” pass values from one response into the next request without scripts
  • Data-driven testing โ€” attach a CSV data table to your environment and run a request against every row, or re-run a single row from a dropdown inside the request panel
  • Compare API responses โ€” diff two responses or two environments side by side, with differences shown in clean JSONPath notation; run bulk comparisons across a full data table for staging-vs-prod regression checks
  • Tests and assertions โ€” write them as table rows (no code) or in JavaScript with a Monaco editor
  • Collection Runner with HTML reports
  • CLI (pmc) for CI/CD pipelines โ€” GitHub Actions, GitLab CI, Jenkins
  • mTLS / client certificate support โ€” certificates stay local, never uploaded
  • One-click import from Postman (v2.0/v2.1), Bruno, Swagger/OpenAPI, and cURL

Postmate Client was built by a solo developer after Postman was blocked at his organization over data privacy concerns. It is designed for developers and teams in security-conscious environments โ€” fintech, healthcare, enterprise โ€” where API payloads, tokens, and certificates must never leave the machine.

Install from the VS Code Marketplace and send your first request in under a minute.

Fiddler

Pricing URL
-
$ Details
-
Platforms
-
Release Date
-

Postmate Client

$ Details
free
Platforms
Windows Mac Linux
Release Date
2025 June
Startup details
Country
United States
State
TX
City
Austin
Founder(s)
Shyam Narayan Yadav
Employees
1 - 9

Fiddler features and specs

  • Comprehensive Debugging
    Fiddler allows for detailed HTTP/HTTPS traffic inspection and debugging, making it invaluable for diagnosing and troubleshooting web applications.
  • Cross-Platform Compatibility
    Works on Windows, macOS, and Linux, providing flexibility to developers working in different environments.
  • Custom Scripting
    Supports custom scripts using FiddlerScript, enabling advanced functionalities and automation of repetitive tasks.
  • User-Friendly Interface
    Provides an intuitive and easy-to-use interface that helps users navigate and utilize its features effectively.
  • Web Debugging Proxy
    Acts as a proxy server that captures traffic between your computer and the internet, which is essential for debugging web applications.

Possible disadvantages of Fiddler

  • Learning Curve
    May require a period of learning and adaptation for users new to the tool or those who are not familiar with HTTP/HTTPS concepts.
  • Resource Intensive
    Can be resource-heavy, especially when capturing and storing large amounts of traffic data, which may slow down your computer.
  • Limited Mobile Support
    Although it can work with mobile devices, setup can be cumbersome and less straightforward compared to desktop debugging.
  • Documentation and Community
    While there is good documentation available, it may not cover all niche use cases, and community support can be hit or miss.
  • SSL Decryption
    Decrypting HTTPS traffic requires additional setup and can introduce security risks if not handled properly.

Postmate Client features and specs

  • Protocols
    REST, GraphQL, and WebSocket
  • Runs in
    VS Code โ€” native extension, no separate app
  • Privacy-Focused
    100% local โ€” no login, no cloud sync, no telemetry
  • Data-Driven Testing
    Run a request against every row of a CSV data table, or re-run any single row
  • Response Comparison
    Diff two responses or environments in JSONPath notation; bulk compare across data tables
  • Collection Runner
    Run full suites with HTML reports
  • Tests & Assertions
    No-code table-based tests, or JavaScript
  • CLI
    pmc โ€” run collections in GitHub Actions, GitLab CI, Jenkins
  • Import/Export
    Import & export Postman format; import Bruno, Swagger/OpenAPI, cURL
  • mTLS Support
    Client certificate support โ€” certificates stay local
  • Pricing
    Free โ€” every feature included, no paid tier

Analysis of Fiddler

Overall verdict

  • Fiddler is considered a good tool, particularly for developers and QA engineers who require a comprehensive and reliable solution for HTTP and HTTPS debugging. Its user-friendly interface and extensive documentation make it accessible, even for those who may not have extensive experience with web development tools.

Why this product is good

  • Fiddler by Telerik is a well-regarded web debugging tool that allows users to monitor, manipulate, and reuse HTTP requests. It's especially popular among developers and testers for its ease of use, robust feature set, and detailed analysis capabilities. It supports various platforms and is versatile enough for debugging tasks such as performance testing, security testing, and web session manipulation. Additionally, Fiddler offers extensive customization through its scripting capabilities, which lets users tailor it to their specific needs.

Recommended for

  • Web Developers
  • QA Engineers
  • Software Testers
  • Network Administrators
  • Anyone needing to debug and analyze HTTP/HTTPS traffic

Analysis of Postmate Client

Overall verdict

  • I don't have verified, up-to-date information about postmateclient.com specifically, so I can't confirm its legitimacy, quality, or safety. There are many similarly-named delivery/courier-related tools and it's easy to confuse legitimate services with unofficial or low-quality clones, so caution is warranted before trusting or paying for this service.

Why this product is good

  • No independently verified reviews, ratings, or reputable coverage were found for this specific site.
  • The name is similar to major brands (e.g., Postmates), which raises the possibility of confusion with unofficial third-party tools.
  • Without clear information on the company behind it, its security practices, or customer support quality, its reliability cannot be confirmed.
  • Domain age, ownership transparency, and user feedback (via trusted review platforms) should be checked before use.

Recommended for

  • Users who have already independently verified the site's legitimacy and ownership.
  • Not recommended for those seeking an official Postmates-affiliated tool without confirming authenticity.
  • Best avoided by users who need to enter sensitive personal or payment information without first confirming security certifications (SSL, privacy policy, business registration).
  • Suitable only for advanced users comfortable doing their own due diligence (checking WHOIS data, reviews on Trustpilot/BBB, etc.) before trusting the service.

Fiddler videos

Fiddler On The Roof, Faith on Film review

More videos:

  • Review - FIDDLER ON THE ROOF WEST END REVIEW | Georgie Ashford
  • Review - Fiddler on the Roof Review

Postmate Client videos

No Postmate Client videos yet. You could help us improve this page by suggesting one.

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Category Popularity

0-100% (relative to Fiddler and Postmate Client)
Monitoring Tools
100 100%
0% 0
API Tools
0 0%
100% 100
Developer Tools
94 94%
6% 6
Security
100 100%
0% 0

Questions & Answers

As answered by people managing Fiddler and Postmate Client.

What makes your product unique?

Postmate Client's answer:

Postmate Client combines three things no other API client does together:

  • Runs natively inside VS Code โ€” no separate app
  • 100% local โ€” no login, no cloud sync, no telemetry
  • Every feature free โ€” no paid tier

Two workflows stand out:

  • Data-driven testing โ€” attach a CSV data table to an environment and every row appears in a dropdown inside the request. Run all rows, or re-run a single failing row with one click.
  • Compare mode โ€” diff responses across two environments in JSONPath notation, even across an entire data table. Staging vs prod regression testing in one click.

Why should a person choose your product over its competitors?

Postmate Client's answer:

Choose Postmate Client if your API data must stay on your machine.

  • vs Postman โ€” Postman (and its VS Code extension) requires an account and syncs to their cloud. Postmate Client has no account to sign into, because nothing leaves your disk.
  • vs Thunder Client โ€” adds full data-driven testing, response comparison, WebSocket support, and a CLI, all free.
  • No paywall anywhere โ€” collection runner, CI/CD CLI, and mTLS support are all included.

If you need shared cloud workspaces for a team, Postman is better at that โ€” Postmate Client is built for developers who want speed and privacy.

How would you describe the primary audience of your product?

Postmate Client's answer:

Developers and QA engineers who test APIs while writing code and want their data to stay local โ€” especially in security-conscious environments (fintech, healthcare, enterprise) where cloud-based API tools are blocked or discouraged by security teams.

Also a natural fit for VS Code users tired of switching to a separate app for API testing.

What's the story behind your product?

Postmate Client's answer:

Postmate Client was built by a solo developer after Postman was blocked at his organization over data privacy concerns โ€” API payloads and tokens syncing to a third-party cloud was an unacceptable risk.

The entire product philosophy stems from that day: no login, no cloud sync, no telemetry, everything stored locally. What started as a personal tool became a full API client for VS Code โ€” and it remains free, with every feature included.

Which are the primary technologies used for building your product?

Postmate Client's answer:

  • TypeScript and the VS Code Extension API
  • Monaco Editor for scripting and diff views
  • Core logic ships as the @postmate/core npm package, which also powers the pmc CLI for CI/CD pipelines

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare Fiddler and Postmate Client

Fiddler Reviews

Top 10 HTTP Client and Web Debugging Proxy Tools (2023)
Next right up is Fiddler. It is one of the most powerful and popular web debugging proxy tools. it can debug and troubleshoot endlessly. What you would come to like is that Fiddler is free and has lots of plug-ins you can use. Knowing it captures, analyze and record HTTP traffic between your device and the server, handling any embedded issues becomes easy.
12 HTTP Client and Web Debugging Proxy Tools
Fiddler is a cross-platform web debugging proxy. It can help manipulate web sessions, inspect HTTPS traffic, and monitor traffic between your computer and the Internet.
Source: geekflare.com
Comparing Charles Proxy, Fiddler, Wireshark, and Requestly
Fiddler is another popular web debugging proxy that runs on Windows. It provides developers with a range of features, such as HTTP/HTTPS traffic capturing, request modification, and performance testing. In addition to these features, Fiddler has a scripting engine called FiddlerScript, which allows for customizing the toolโ€™s behavior. This scripting engine enables developers...
Source: dev.to
73 Best SEO tools 2021 โ€“ The Most Epic List You Shouldnโ€™t Miss
The answer is simple โ€“ if you are looking for an SEO site tool that wonโ€™t freeze your browser (a common problem with most plugins), then Fiddler is your ultimate debugging tool.

Postmate Client Reviews

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What are some alternatives?

When comparing Fiddler and Postmate Client, you can also consider the following products

Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy

Postman - The Collaboration Platform for API Development

Thunder Client - Rest API client for VS Code, lightweight Postman alternative

Horangi - Horangi is a leading cyber-security solution that provides instant response and threat detection for companies who lack the time and expertise to monitor their system.

Bruno - Bruno is a Git-integrated, fully offline, and open-source API client

Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.